Adding Node.js version file support

In scope of this release we add the node-version-file input and update actions/cache dependency to the latest version.

Adding Node.js version file support

The new input (node-version-file) provides functionality to specify the path to the file containing Node.js's version with such behaviour:

• If the file does not exist the action will throw an error.
• If you specify both node-version and node-version-file inputs, the action will use value from the node-version input and throw the following warning: Both node-version and node-version-file inputs are specified, only node-version will be used.
• For now the action does not support all of the variety of values for Node.js version files. The action can handle values according to the documentation and values with v prefix (v14)

steps:
  - uses: actions/checkout@v2
  - name: Setup node from node version file
    uses: actions/setup-node@v2
    with:
      node-version-file: '.nvmrc'
  - run: npm install
  - run: npm test

Update actions/cache dependency to 1.0.8 version.

We updated actions/cache dependency to the latest version (1.0.8). For more information please refer to the toolkit/cache.