Fixup caching step of Github workflow. Correct path to environment.yml

.github/workflows/build.yml

@@ -21,13 +21,13 @@ jobs:
       - name: Cache conda
         uses: actions/cache@v2
         env:
-          # Increase this value to reset cache if etc/example-environment.yml has not changed
+          # Increase this value to reset cache if environment.yml has not changed
           CACHE_NUMBER: 0
         with:
           path: ~/conda_pkgs_dir
           key:
             ${{ runner.os }}-conda-${{ env.CACHE_NUMBER }}-${{
-            hashFiles('etc/example-environment.yml') }}
+            hashFiles('environment.yml') }}
       - uses: conda-incubator/setup-miniconda@v2
         with:
           activate-environment: test