[deployphp#2197] Moved E2E tests to separate job

Moved E2E tests to separate job and added docker-compose cache
to slightly improve stack build times.

.github/workflows/test.yml

@@ -33,8 +33,30 @@ jobs:
     - name: Run test suite
       run: composer test
 
+  e2e:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - uses: satackey/[email protected]
+      continue-on-error: true
+
     - name: Build the docker-compose stack
       run: cd test/docker && docker-compose build
 
+    - name: Cache Composer packages
+      id: composer-cache
+      uses: actions/cache@v2
+      with:
+        path: vendor
+        key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-php-
+
+    - name: Install dependencies
+      if: steps.composer-cache.outputs.cache-hit != 'true'
+      run: composer install --prefer-dist --no-progress --no-suggest
+
     - name: Run E2E test suite
       run: cd test/docker && docker-compose up --abort-on-container-exit