Fix expose of Haq module within haskell spec

Fix the setup of this Haskell project within CircleCI and when setting
up on a new machine or within Docker. This required that `Haq` not be
considered a Library (without an executable), but instead an exposed
module that was built and included within both the base project, as well
as its tests.

This should resolve problems that where occurring when running
`cabal install`

== Notes:
- Change the order of `cabal update` with `cabal sandbox init`, since
  update will only run it there is a sandbox available, which is not
  present in the Haskell image container

- Add `--enable-tests` and `--enable-documentation` to cabal install to
  slience other warnings

== References:
- [How to write a Haskell program \- HaskellWiki]
  (https://wiki.haskell.org/How_to_write_a_Haskell_program#Add_some_tests)

- [cabal \- Set up Haskell Project and run tests \- Stack Overflow]
  (https://stackoverflow.com/questions/38928802/set-up-haskell-project-and-run-tests)

- [Cabal\-Install \- HaskellWiki]
  (https://wiki.haskell.org/Cabal-Install)

- [Invoking Haddock — Haddock 1\.0 documentation]
  (http://haskell-haddock.readthedocs.io/en/latest/invoking.html)

- [new\-build failure with custom\-setup when setup\-depends don't
  contain Cabal · Issue \#4288 · haskell/cabal]
  (haskell/cabal#4288)

- [2\.1\. Configuration — Cabal <release> User's Guide]
  (https://www.haskell.org/cabal/users-guide/installing-packages.html)

Author: Sonna

.circleci/config.yml

@@ -5,19 +5,20 @@ jobs:
     - image: haskell:latest
     steps:
     - checkout
-    - run: cabal update
     - run: cabal sandbox init
-    - run: cabal install -j
+    - run: cabal update
+    # - run: cabal install -j
+    - run: cabal install --enable-tests --enable-documentation
     - run: cabal build
 
   test:
     docker:
     - image: haskell:latest
     steps:
     - checkout
-    - run: cabal update
     - run: cabal sandbox init
-    - run: cabal install --enable-tests
+    - run: cabal update
+    - run: cabal install --enable-tests --enable-documentation
     - run: cabal test
 
 workflows:

toy-robot-haskell.cabal

@@ -46,23 +46,24 @@ build-type:          Simple
 extra-source-files:  ChangeLog.md
 
 -- Constraint on the version of Cabal needed to build this package.
-cabal-version:       >=1.10
+-- cabal-version:       >=1.10
+cabal-version:       >=2.0
 
 
-library haq
---   other-modules:      Haq
-  exposed-modules:     Haq
-  build-depends:       base >=4.10 && <4.11
-  hs-source-dirs:      src
-  default-language:    Haskell2010
+-- library haq
+-- --   other-modules:      Haq
+--   exposed-modules:     Haq
+--   build-depends:       base >=4.10 && <4.11
+--   hs-source-dirs:      src
+--   default-language:    Haskell2010
 
 
 executable toy-robot-haskell
   -- .hs or .lhs file containing the Main module.
   main-is:             Main.hs
 
   -- Modules included in this executable, other than Main.
-  -- other-modules:      Haq
+  other-modules:      Haq
   -- exposed-modules:    Haq
 
   -- LANGUAGE extensions used by modules in this package.
@@ -92,9 +93,8 @@ test-suite tests
   main-is: HSpecTests.hs
   hs-source-dirs:      src, spec
   build-depends:       base,
-                       haq,
+--                       haq,
                        hspec                >= 1.8
   default-language:    Haskell2010
   -- Required due to including src/Haq.hs
   other-modules:      Haq
-