Use GHA paths (#4668)

Author: paulb777

.github/workflows/actions.yml

@@ -0,0 +1,15 @@
+name: check
+
+on: [pull_request]
+
+jobs:
+  check:
+    runs-on: macOS-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Check
+      run: |
+        brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/e3496d9/Formula/clang-format.rb
+        brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/7963c3d/Formula/swiftformat.rb
+        pip install flake8
+        ./scripts/check.sh --test-only

.github/workflows/check.yml

@@ -0,0 +1,18 @@
+name: core
+
+on:
+  pull_request:
+    paths:
+    - 'FirebaseCore**'
+
+jobs:
+  core:
+    runs-on: macOS-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up
+      run: |
+        bundle install
+        bundle exec pod --version
+    - name: FirebaseCore
+      run: ./scripts/pod_lib_lint.rb FirebaseCore.podspec --platforms=ios

.github/workflows/core.yml

@@ -0,0 +1,20 @@
+name: dynamiclinks
+
+on:
+  pull_request:
+    paths:
+    - 'Firebase/DynamicLinks**'
+    - 'FirebaseDynamicLinks**'
+    - 'Example/DynamicLinks**'
+
+jobs:
+  dynamiclinks:
+    runs-on: macOS-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up
+      run: |
+        bundle install
+        bundle exec pod --version
+    - name: FirebaseDynamicLinks
+      run: ./scripts/pod_lib_lint.rb FirebaseDynamicLinks.podspec