Revert "Upgrade checkout to v1.1.0 to better support scripting git. (#56)"

This reverts commit 0b496e91ec.

.gitmodules

@@ -1,4 +0,0 @@
-[submodule "submodule-level-2"]
-	path = submodule-level-2
-	url = ./
-	branch = test-data/v2/submodule-level-2

LICENSE

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+
+The MIT License (MIT)
+
+Copyright (c) 2018 GitHub, Inc. and contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

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+# checkout
+
+This action checks out your repository to `$GITHUB_WORKSPACE`, so that your workflow can access the contents of your repository.
+
+By default, this is equivalent to running `git fetch` and `git checkout $GITHUB_SHA`, so that you'll always have your repo contents at the version that triggered the workflow.
+See [here](https://help.github.com/en/articles/events-that-trigger-workflows) to learn what `$GITHUB_SHA` is for different kinds of events.
+
+# Usage
+
+See [action.yml](action.yml)
+
+Basic:
+
+```yaml
+steps:
+- uses: actions/checkout@master
+- uses: actions/setup-node@master
+  with:
+    node-version: 10.x 
+- run: npm install
+- run: npm test
+```
+
+By default, the branch or tag ref that triggered the workflow will be checked out. If you wish to check out a different branch, specify that using `with.ref`:
+
+```yaml
+- uses: actions/checkout@master
+  with:
+    ref: some-branch
+```
+
+For more details, see [Contexts and expression syntax for GitHub Actions](https://help.github.com/en/articles/contexts-and-expression-syntax-for-github-actions)
+
+# License
+
+The scripts and documentation in this project are released under the [MIT License](LICENSE)

action.yml

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+name: 'Checkout'
+description: 'Checkout a Git repository.'
+inputs: 
+  repository:
+    description: 'Repository name'
+  ref:
+    description: 'Ref to checkout (SHA, branch, tag)'
+  token:
+    description: 'Access token for clone repository'
+  clean:
+    description: 'If true, execute `execute git clean -ffdx && git reset --hard HEAD` before fetching'
+    default: true
+  submodules:
+    description: 'Whether to include submodules: false to exclude submodules, true to include only one level of submodules, or recursive to recursively clone submodules; defaults to false'
+  lfs:
+    description: 'Whether to download Git-LFS files; defaults to false'
+  fetch-depth:
+    description: 'The depth of commits to ask Git to fetch; defaults to no limit'  
+  path:
+    description: 'Optional path to check out source code'  
+runs:
+  # Plugins live on the runner and are only available to a certain set of first party actions.
+  plugin: 'checkout'