Improve CI:

* Use new version of git-modtime

* Fixed caching on MacOS and Windows:
  * Disable caching of stack-work on MacOS, problems running cached binaries.
  * Add caching stack-root on Windows

* Update to newer version of shc

.github/workflows/haskell.yml

@@ -38,22 +38,34 @@ jobs:
     env:
       STACK_YAML: stack.yaml
       STACK_ARGS: '--resolver ${{ matrix.resolver }}'
-      cache-version: v2 # bump up this version to invalidate currently stored cache
+      cache-version: v5 # bump up this version to invalidate currently stored cache
     steps:
     - uses: actions/checkout@v2
 
     - name: Cache
       id: cache
       uses: actions/cache@v2
+      if: matrix.os != 'macos-latest'
       with:
         path: |
           ~/.stack
+          .stack-work
           Color/.stack-work
         key: ${{ runner.os }}-${{ matrix.resolver }}-${{ env.cache-version }}
         restore-keys: |
           ${{ runner.os }}-${{ matrix.resolver }}-${{ env.cache-version }}
+    - name: Cache
+      id: cache-macos
+      uses: actions/cache@v2
+      if: matrix.os == 'macos-latest'
+      with:
+        path: |
+          ~/.stack
+        key: ${{ runner.os }}-${{ matrix.resolver }}-${{ env.cache-version }}
+        restore-keys: |
+          ${{ runner.os }}-${{ matrix.resolver }}-${{ env.cache-version }}
     - name: Workaround setup-exe-cache failure on macos
-      if: steps.cache.outputs.cache-hit == 'true' && matrix.os == 'macos-latest'
+      if: steps.cache-macos.outputs.cache-hit == 'true' && matrix.os == 'macos-latest'
       run: |
         rm -r ~/.stack/setup-exe-cache
     - name: Windows Cache
@@ -62,7 +74,8 @@ jobs:
       if: matrix.os == 'windows-latest'
       with:
         path: |
-          ~/AppData/Local/Programs/stack
+          C:\\Users\\RUNNER~1\\AppData\\Roaming\\stack
+          C:\\Users\\RUNNER~1\\AppData\\Local\\Programs\\stack
         key: ${{ runner.os }}-${{ matrix.resolver }}-programs-${{ env.cache-version }}
         restore-keys: |
           ${{ runner.os }}-${{ matrix.resolver }}-programs-${{ env.cache-version }}
@@ -77,7 +90,7 @@ jobs:
       run: |
         set -ex
         curl -sSL https://get.haskellstack.org/ | sh -s - -f
-        curl -sSL https://gist.githubusercontent.com/lehins/fd36a8cc8bf853173437b17f6b6426ad/raw/4702d0252731ad8b21317375e917124c590819ce/git-modtime.hs -o git-modtime.hs
+        curl -sSL https://raw.githubusercontent.com/lehins/utils/786c3fe7e9e1345d7b403019f52e344627224edf/haskell/git-modtime/git-modtime.hs -o git-modtime.hs
         [ -n "${{ matrix.ghc }}" ] && [ "${{ matrix.os }}" == "ubuntu-latest" ] && STACK_ARGS="$STACK_ARGS --system-ghc"
         [ -n "${{ matrix.stack-yaml }}" ] && STACK_YAML=${{ matrix.stack-yaml }}
         stack $STACK_ARGS runghc git-modtime.hs
@@ -91,7 +104,7 @@ jobs:
         if [ "${{ matrix.os }}.${{ matrix.resolver }}" == "ubuntu-latest.lts-14" ] && [ -n "${COVERALLS_TOKEN}" ]; then
           stack $STACK_ARGS test Color:tests --coverage --haddock --no-haddock-deps
           stack $STACK_ARGS hpc report --all
-          curl -L https://github.com/lehins/stack-hpc-coveralls/releases/download/v0.0.6.0/shc.tar.gz | tar xz shc
+          curl -L https://github.com/rubik/stack-hpc-coveralls/releases/download/v0.0.6.1/shc-linux-x64-8.8.4.tar.bz2 | tar xj shc
           ./shc --repo-token="$COVERALLS_TOKEN" --partial-coverage --fetch-coverage combined custom
         else
           stack $STACK_ARGS test Color:tests Color:doctests --bench --no-run-benchmarks --haddock --no-haddock-deps