pin actions/checkout version to v2 (#1617)

.github/workflows/docker_builds.yml

@@ -1,10 +1,10 @@
 name: Publish Docker
 on:
-  push: 
+  push:
     branches:
-      - master 
-  release: 
-    types: 
+      - master
+  release:
+    types:
        - created
 
 jobs:
@@ -19,7 +19,7 @@ jobs:
       if: contains(github.ref, 'refs/tags/')
       id: get_version
       run: echo ::set-output name=VERSION::${GITHUB_REF/refs\/tags\//}
-    - uses: actions/checkout@2.14
+    - uses: actions/checkout@v2
     - name: Publish Releases to Docker
       # only on releases
       uses: elgohr/Publish-Docker-Github-Action@master
@@ -42,5 +42,3 @@ jobs:
         dockerfile: docker/Dockerfile
         buildargs: PYTHON_VERSION=${{ matrix.python_version }},PYTORCH_VERSION=${{ matrix.pytorch_version }},LIGHTNING_VERSION=${{ steps.get_version.outputs.VERSION }}
         tags: "latest_py${{ matrix.python_version }}_torch${{ matrix.pytorch_version }}"
-  
-

.github/workflows/pypi-release.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@master
+    - uses: actions/checkout@v2
     - name: Set up Python 3.7
       uses: actions/setup-python@v1
       with:
@@ -30,7 +30,7 @@ jobs:
     - name: Build
       run: >-
         python setup.py sdist bdist_wheel
-    
+
     # We do this, since failures on test.pypi aren't that bad
     - name: Publish to Test PyPI
       if: startsWith(github.event.ref, 'refs/tags') || github.event_name == 'release'

.github/workflows/rebase.yml

@@ -10,7 +10,7 @@ jobs:
     if: github.event.issue.pull_request != '' && contains(github.event.comment.body, '/rebase')
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@master
+    - uses: actions/checkout@v2
       with:
         fetch-depth: 0
     - name: Automatic Rebase
@@ -23,4 +23,4 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Always run
-        run: echo "This job is used to prevent the workflow to fail when all other jobs are skipped."
+        run: echo "This job is used to prevent the workflow to fail when all other jobs are skipped."