chore(ci): Remove GitHub actions for now

.github/workflows/main.yml

@@ -1,22 +0,0 @@
-on: [push, pull_request]
-
-jobs:
-  ci:
-    name: CI
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@master
-        with:
-          fetch-depth: 50
-      - name: Install Rust Stable
-        run: |
-          rustc -vV
-          rustup update stable
-          rustup default stable
-          rustc -vV
-      - name: Run rustfmt
-        run: cargo fmt -- --check
-      - name: Run clippy
-        run: cargo clippy -- -Dwarnings
-      - name: Run tests
-        run: cargo test --verbose