build: fix CI for forks and related docs (#3847)

.github/workflows/build.yml

@@ -104,7 +104,8 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v1
         with:
-          path: ./src/github.com/${{ github.repository }}
+          # Checkout into a fixed path to avoid import path problems on go < 1.11
+          path: ./src/github.com/rclone/rclone
 
       - name: Install Go
         uses: actions/setup-go@v1
@@ -201,7 +202,8 @@ jobs:
         env:
           RCLONE_CONFIG_PASS: ${{ secrets.RCLONE_CONFIG_PASS }}
         # working-directory: '$(modulePath)'
-        if: matrix.deploy && github.head_ref == ''
+        # Deploy binaries if enabled in config && not a PR && not a fork
+        if: matrix.deploy && github.head_ref == '' && github.repository == 'rclone/rclone'
 
   xgo:
     timeout-minutes: 60
@@ -213,7 +215,8 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v1
         with:
-          path: ./src/github.com/${{ github.repository }}
+          # Checkout into a fixed path to avoid import path problems on go < 1.11
+          path: ./src/github.com/rclone/rclone
 
       - name: Set environment variables
         shell: bash
@@ -247,4 +250,5 @@ jobs:
           make circleci_upload
         env:
           RCLONE_CONFIG_PASS: ${{ secrets.RCLONE_CONFIG_PASS }}
-        if: github.head_ref == ''
+        # Upload artifacts if not a PR && not a fork
+        if: github.head_ref == '' && github.repository == 'rclone/rclone'

CONTRIBUTING.md

@@ -82,13 +82,9 @@ You patch will get reviewed and you might get asked to fix some stuff.
 If so, then make the changes in the same branch, squash the commits,
 rebase it to master then push it to GitHub with `--force`.
 
-## Enabling CI for your fork ##
+## CI for your fork ##
 
-The CI config files for rclone have taken care of forks of the project, so you can enable CI for your fork repo easily.
-
-rclone currently uses [Travis CI](https://travis-ci.org/), [AppVeyor](https://ci.appveyor.com/), and
-[Circle CI](https://circleci.com/) to build the project. To enable them for your fork, simply go into their
-websites, find your fork of rclone, and enable building there.
+rclone currently uses [GitHub Actions](https://github.com/rclone/rclone/actions) to build and test the project, which should be automatically available for your fork too from the `Actions` tab in your repository.
 
 ## Testing ##