Use rhysd/action-setup-vim@v1 in gha tests

Makes it easier to support multiple neovim versions

Author: mfussenegger

.github/workflows/tests.yml

@@ -10,6 +10,9 @@ jobs:
   build:
     name: Run tests
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        neovim_version: ['nightly']
 
     steps:
       - uses: actions/checkout@v2
@@ -25,8 +28,12 @@ jobs:
           git clone --depth 1 https://github.com/nvim-lua/plenary.nvim ~/.local/share/nvim/site/pack/vendor/start/plenary.nvim
           ln -s "$(pwd)" ~/.local/share/nvim/site/pack/vendor/start
 
+      - name: Setup neovim
+        uses: rhysd/action-setup-vim@v1
+        with:
+          neovim: true
+          version: ${{ matrix.neovim_version }}
+
       - name: Run tests
         run: |
-          curl -OL https://raw.githubusercontent.com/norcalli/bot-ci/master/scripts/github-actions-setup.sh
-          source github-actions-setup.sh nightly-x64
           nvim --headless --noplugin -u tests/minimal.vim -c "PlenaryBustedDirectory tests/ {minimal_init = 'tests/minimal.vim'}"