Update Rust CI (#29)

Author: lpil

.github/workflows/ci.yml

@@ -1,11 +1,17 @@
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - "*"
+  pull_request:
 name: CI
 jobs:
   lint:
     name: Lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
@@ -38,7 +44,7 @@ jobs:
         os: [ubuntu-latest, windows-latest, macOS-latest]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
@@ -62,7 +68,7 @@ jobs:
     name: cargo-deny check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - uses: EmbarkStudios/cargo-deny-action@v1
 
   publish-check: