build(deps): bump actions/cache from 2.1.5 to 2.1.6 (#258)

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
           node-version: '12'
 
       - name: Cache node_modules
-        uses: actions/[email protected].5
+        uses: actions/[email protected].6
         id: cached-node_modules
         with:
           path: |
@@ -34,7 +34,7 @@ jobs:
           python-version: '3.8'
 
       - name: Cache pip
-        uses: actions/[email protected].5
+        uses: actions/[email protected].6
         with:
           path: ~/.cache/pip
           key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}-${{ hashFiles('requirements-constraints.txt') }}-${{ hashFiles('dev-requirements.txt') }}