Switch to stable toolchain

.github/workflows/main.yml

@@ -27,12 +27,6 @@ jobs:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2
 
-      - name: Install nightly
-        uses: actions-rs/toolchain@v1
-        with:
-          toolchain: nightly
-          override: true
-
       # Runs a single command using the runners shell
       - name: Build site
         run: |