actually update the CI file (never saved)

.github/workflows/ci.yml

@@ -1,23 +1,31 @@
-on: [push, pull_request]
-
-name: lints
+name: ci
+on:
+  push:
+    branches:
+      - main
+  pull_request:
 
 jobs:
-  combo:
-    name: Clippy + rustfmt
+  lints:
+    name: lints
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
         uses: actions/checkout@v2
 
-      - name: Install nightly toolchain
+      - name: Install beta toolchain
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: nightly
+          toolchain: beta
           override: true
           components: rustfmt, clippy
 
+      - name: Set up cache
+        uses: Swatinem/rust-cache@v1
+        with:
+          cache-on-failure: true
+
       - name: Run cargo fmt
         uses: actions-rs/cargo@v1
         with:
@@ -28,4 +36,55 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: clippy
-          args: --all-features -- -D warnings
+          args: --tests -- -D warnings
+
+  no_std:
+    name: no_std
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+
+      - name: Install beta toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: beta
+          target: armv7a-none-eabi
+          override: true
+
+      - name: Set up cache
+        uses: Swatinem/rust-cache@v1
+        with:
+          cache-on-failure: true
+
+      - name: Build binary for armv7a-none-eabi
+        uses: actions-rs/cargo@v1
+        with:
+          command: rustc
+          args: --target=armv7a-none-eabi --manifest-path=ensure_no_std/Cargo.toml
+
+  tests:
+    name: tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+
+      - name: Install beta toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: beta
+          override: true
+
+      - name: Set up cache
+        uses: Swatinem/rust-cache@v1
+        with:
+          cache-on-failure: true
+
+      - name: Run cargo test
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --all-features