Update cffi to 1.12.0 (#552)

This PR updates [cffi](https://pypi.org/project/cffi) from **1.11.5** to **1.12.0**.



<details>
  <summary>Changelog</summary>
  
  
   ### 1.12
   ```
   =====

* `Direct support for pkg-config`__.

* ``ffi.from_buffer()`` takes a new optional *first* argument that gives
  the array type of the result.  It also takes an optional keyword argument
  ``require_writable`` to refuse read-only Python buffers.

* ``ffi.new()``, ``ffi.gc()`` or ``ffi.from_buffer()`` cdata objects
  can now be released at known times, either by using the ``with``
  keyword or by calling the new ``ffi.release()``.

* Windows, CPython 3.x: cffi modules are linked with ``python3.dll``
  again.  This makes them independant on the exact CPython version,
  like they are on other platforms.  **It requires virtualenv 16.0.0.**

* Accept an expression like ``ffi.new(&quot;int[4]&quot;, p)`` if ``p`` is itself
  another cdata ``int[4]``.

* CPython 2.x: ``ffi.dlopen()`` failed with non-ascii file names on Posix

* CPython: if a thread is started from C and then runs Python code (with
  callbacks or with the embedding solution), then previous versions of
  cffi would contain possible crashes and/or memory leaks.  Hopefully,
  this has been fixed (see `issue 362`_).

* Support for ``ffi.cdef(..., pack=N)`` where N is a power of two.
  Means to emulate ``pragma pack(N)`` on MSVC.  Also, the default on
  Windows is now ``pack=8``, like on MSVC.  This might make a difference
  in corner cases, although I can&#39;t think of one in the context of CFFI.
  The old way ``ffi.cdef(..., packed=True)`` remains and is equivalent
  to ``pack=1`` (saying e.g. that fields like ``int`` should be aligned
  to 1 byte instead of 4).

.. __: cdef.htmlpkgconfig
.. _`issue 362`: https://bitbucket.org/cffi/cffi/issues/362/


Older Versions
==============
   ```
   
  
</details>


 

<details>
  <summary>Links</summary>
  
  - PyPI: https://pypi.org/project/cffi
  - Changelog: https://pyup.io/changelogs/cffi/
  - Docs: http://cffi.readthedocs.org
</details>

Author: pyup-bot

requirements.txt

@@ -254,34 +254,34 @@ regex==2019.02.07 \
     --hash=sha256:0969fdb610435d7f49dc5518f7642d7b1319ef19f0c3f1bd4d972afbb9877aa7 \
     --hash=sha256:3679f269790c87bd04e003e60e098b1be5392f17c48d28c2a3b9d16b3dcbca2a \
     --hash=sha256:4a1a1d963f462c13722b34ef1f82c4707091b0a3fb9b5fd79b6670c38b734095
-cffi==1.11.5 \
-    --hash=sha256:1b0493c091a1898f1136e3f4f991a784437fac3673780ff9de3bcf46c80b6b50 \
-    --hash=sha256:87f37fe5130574ff76c17cab61e7d2538a16f843bb7bca8ebbc4b12de3078596 \
-    --hash=sha256:1553d1e99f035ace1c0544050622b7bc963374a00c467edafac50ad7bd276aef \
-    --hash=sha256:151b7eefd035c56b2b2e1eb9963c90c6302dc15fbd8c1c0a83a163ff2c7d7743 \
-    --hash=sha256:edabd457cd23a02965166026fd9bfd196f4324fe6032e866d0f3bd0301cd486f \
-    --hash=sha256:ba5e697569f84b13640c9e193170e89c13c6244c24400fc57e88724ef610cd31 \
-    --hash=sha256:79f9b6f7c46ae1f8ded75f68cf8ad50e5729ed4d590c74840471fc2823457d04 \
-    --hash=sha256:b0f7d4a3df8f06cf49f9f121bead236e328074de6449866515cea4907bbc63d6 \
-    --hash=sha256:4c91af6e967c2015729d3e69c2e51d92f9898c330d6a851bf8f121236f3defd3 \
-    --hash=sha256:7a33145e04d44ce95bcd71e522b478d282ad0eafaf34fe1ec5bbd73e662f22b6 \
-    --hash=sha256:95d5251e4b5ca00061f9d9f3d6fe537247e145a8524ae9fd30a2f8fbce993b5b \
-    --hash=sha256:b75110fb114fa366b29a027d0c9be3709579602ae111ff61674d28c93606acca \
-    --hash=sha256:ae5e35a2c189d397b91034642cb0eab0e346f776ec2eb44a49a459e6615d6e2e \
-    --hash=sha256:fdf1c1dc5bafc32bc5d08b054f94d659422b05aba244d6be4ddc1c72d9aa70fb \
-    --hash=sha256:9d1d3e63a4afdc29bd76ce6aa9d58c771cd1599fbba8cf5057e7860b203710dd \
-    --hash=sha256:be2a9b390f77fd7676d80bc3cdc4f8edb940d8c198ed2d8c0be1319018c778e1 \
-    --hash=sha256:ed01918d545a38998bfa5902c7c00e0fee90e957ce036a4000a88e3fe2264917 \
-    --hash=sha256:857959354ae3a6fa3da6651b966d13b0a8bed6bbc87a0de7b38a549db1d2a359 \
-    --hash=sha256:2ba8a45822b7aee805ab49abfe7eec16b90587f7f26df20c71dd89e45a97076f \
-    --hash=sha256:a36c5c154f9d42ec176e6e620cb0dd275744aa1d804786a71ac37dc3661a5e95 \
-    --hash=sha256:e55e22ac0a30023426564b1059b035973ec82186ddddbac867078435801c7801 \
-    --hash=sha256:3eb6434197633b7748cea30bf0ba9f66727cdce45117a712b29a443943733257 \
-    --hash=sha256:ecbb7b01409e9b782df5ded849c178a0aa7c906cf8c5a67368047daab282b184 \
-    --hash=sha256:770f3782b31f50b68627e22f91cb182c48c47c02eb405fd689472aa7b7aa16dc \
-    --hash=sha256:d5d8555d9bfc3f02385c1c37e9f998e2011f0db4f90e250e5bc0c0a85a813085 \
-    --hash=sha256:3c85641778460581c42924384f5e68076d724ceac0f267d66c757f7535069c93 \
-    --hash=sha256:e90f17980e6ab0f3c2f3730e56d1fe9bcba1891eeea58966e89d352492cc74f4
+cffi==1.12.0 \
+    --hash=sha256:e5eb00a6e1058806a41e3f5a30e4c826ec97d98957302c78909fb8ee98d0266e \
+    --hash=sha256:830831d20030c17d62b7ca3987a09f02c193ff2d2c46dc0dff53d89071dd806e \
+    --hash=sha256:11651532fefba063d372e41826ab669b666d7a92e90dd019f31aefa7cf18e0e0 \
+    --hash=sha256:8a1f16671de9cd41b508f9b2c82de2523f568103b4c32cdeee3c6ed777005766 \
+    --hash=sha256:dfe74188ee1afd0ebfeff31b056aac8b72016f6b0364f90eb3284dc29bf1619a \
+    --hash=sha256:84fe536dc89877b722b5b4ea578f5beac60759363513aeb1df6ec914c6dd6ba1 \
+    --hash=sha256:2e556610fcf5d4c41d480221dec071d517096ff452053b6f4eacfa20fec0dbce \
+    --hash=sha256:bedbb01c0e4fb12f41b2c951723acb4e8305892598e391b89d6a4e6ba5989a63 \
+    --hash=sha256:ad86d01920b90384d7b2fe0df7e75dc06562471e14aa0905351fecd31007016b \
+    --hash=sha256:b107c3f195af098e2b2ea9cc55074e15ee9af6449e63d58ff5b0b75841c49833 \
+    --hash=sha256:be8a266b312707584762036c65d5aa34c56319c6e60536ad8d3f1255d209b2a7 \
+    --hash=sha256:3991da7c291c8c80a4c53303e0abb857bc3598af27fbe203214ddd13dc7cf33a \
+    --hash=sha256:22151b858c916f0765734bcfbf69a986b127260f95f5cb829128c02863c14626 \
+    --hash=sha256:1ec69cca03f9e8e6e2e835f44a1572e0b6d6130aa71a2100459ee33a6c370e04 \
+    --hash=sha256:598fcf6173ea45e5c82ca525cf47a956d1406e8f350bd471049630c4897c8f0a \
+    --hash=sha256:b8a36ff55ec3d22bd4c2baac080b48a9c9fe0af5df363fa1dee7c334dfb06519 \
+    --hash=sha256:116b32a34c862dac9a0c8c28e68fa7d63750068443d0bb595c090c70de7bf080 \
+    --hash=sha256:fa1e30ea308da2ffa91a35042e612340e7c7fcd8614581c85139850b2e18fd17 \
+    --hash=sha256:39f47648b5f2755aa977b37fc49581bdd3d0a500eb31f61c034af2ff05d6f56f \
+    --hash=sha256:22558c0c4d9640b0869c51bbd8761dbf610cec03db6c7ec8471c4371e7450141 \
+    --hash=sha256:e0eaa6da93e87229f2d8e133c3baa459ed626e374d20486e2dc94a8e9d2f019d \
+    --hash=sha256:9b658f51245abb1ed6a5467ca58933e912ea6039327745655de6753f848fb98a \
+    --hash=sha256:6c96839af24f3edd2f6b44f8b7cf5d1fc1ad1f0da1c9fb2227a4239707adfdb7 \
+    --hash=sha256:ddf1824a0f04f324f1d380f44893abb57394379763e4ed6200bc188f33b32325 \
+    --hash=sha256:430fa07eb38761a720aac338202fc15cbe9897deef50fa7f8afc2217b85213da \
+    --hash=sha256:0fd93b32d96d7ce46d0fb0db6d82f73e2e6ee37696a0fed152240c780ff99d16 \
+    --hash=sha256:08090454ff236239e583a9119d0502a6b9817594c0a3714dd1d8593f2350ba11
 olefile==0.46 \
     --hash=sha256:133b031eaf8fd2c9399b78b8bc5b8fcbe4c31e85295749bb17a87cba8f3c3964
 idna==2.8 \