Move eigen dl version to single file, update to 3.3.2

.appveyor.yml

@@ -23,9 +23,10 @@ install:
       conda install -y -q pytest numpy scipy
     }
 - ps: |
-    Start-FileDownload 'http://bitbucket.org/eigen/eigen/get/3.3.0.zip'
-    7z x 3.3.0.zip -y > $null
-    $env:CMAKE_INCLUDE_PATH = "eigen-eigen-26667be4f70b"
+    $eigen = Get-Content -head 2 .eigen-build-version
+    Start-FileDownload "http://bitbucket.org/eigen/eigen/get/$($eigen[0]).zip"
+    7z x "$($eigen[0]).zip" -y > $null
+    $env:CMAKE_INCLUDE_PATH = $eigen[1]
 build_script:
 - cmake -A "%CMAKE_ARCH%" -DPYBIND11_WERROR=ON
 - set MSBuildLogger="C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"

.eigen-build-version

@@ -0,0 +1,5 @@
+3.3.2
+eigen-eigen-da9b4e14c255
+# This is the version and extracted directory used for appveyor and travis-ci
+# builds.  The first line is the eigen version to download, the second is the
+# extracted directory name.  These comments must stay after the first two lines.

.travis.yml

@@ -124,9 +124,9 @@ install:
   else
     pip install numpy scipy pytest
 
-    wget -q -O eigen.tar.gz https://bitbucket.org/eigen/eigen/get/3.3.0.tar.gz
-    tar xzf eigen.tar.gz
-    export CMAKE_EXTRA_ARGS="${CMAKE_EXTRA_ARGS} -DCMAKE_INCLUDE_PATH=$PWD/eigen-eigen-26667be4f70b"
+    eigen=($(head -n 2 .eigen-build-version))
+    curl https://bitbucket.org/eigen/eigen/get/${eigen[0]}.tar.bz2 | tar xj
+    export CMAKE_EXTRA_ARGS="${CMAKE_EXTRA_ARGS} -DCMAKE_INCLUDE_PATH=$PWD/${eigen[1]}"
   fi
 script:
 - $SCRIPT_RUN_PREFIX cmake ${CMAKE_EXTRA_ARGS}