Merge rust-bitcoin/rust-secp256k1#420: Improve CI script

58db1b6753 Run WASM for multiple toolchains (Tobin Harding)
946ac3b51e Do docs build in Nightly job (Tobin Harding)
f7bc7d3728 Install clang to run adress sanitizer (Tobin Harding)
96685c571d Remove unnecessary matrix (Tobin Harding)
a8a679ed7d Re-name nightly CI job to Nightly (Tobin Harding)
9c9d622b0e Remove trailing whitespace (Tobin Harding)

Pull request description:

  Improve the CI pipeline. Done while investigating #419. This PR now only includes the GitHub actions changes, I'm moving the `test.sh` changes to a https://github.com/rust-bitcoin/rust-secp256k1/pull/422 because they cannot be merged yet.

  (Please note, this PR has been heavily re-worked so discussion below may be confusing to reviewers new to the PR.)

ACKs for top commit:
  apoelstra:
    ACK 58db1b6753
  thomaseizinger:
    ACK 58db1b6753

Tree-SHA512: 5520cf7a7ea0ba701aeaf6b97150416192c0629df8b65545a20d8937a4d76bd323a0d7a875deccb7ce9adc4f3a423e6cd27b300682f206f79407f5ab4eaa5ddb

.github/workflows/rust.yml

@@ -3,21 +3,19 @@ on: [push, pull_request]
 name: Continuous integration
 
 jobs:
-  bench_nightly:
-    name: Nightly - ASan + Bench
+  Nightly:
+    name: Nightly - ASan + Bench + Docs
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        rust:
-          - nightly
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v2
+      - name: Install clang for ASan
+        run: sudo apt-get install -y clang
       - name: Checkout Toolchain
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: ${{ matrix.rust }}
+          toolchain: nightly
           override: true
           components: rust-src
       - name: Running address sanitizer
@@ -28,27 +26,17 @@ jobs:
         env:
           DO_BENCH: true
         run: ./contrib/test.sh
+      - name: Building docs
+        env:
+          DO_DOCS: true
+        run: ./contrib/test.sh
 
   Tests:
     name: Tests
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        include:
-          - rust: stable
-            env:
-              DO_FEATURE_MATRIX: true
-              DO_WASM: true
-          - rust: beta
-            env:
-              DO_FEATURE_MATRIX: true
-          - rust: nightly
-            env:
-              DO_FEATURE_MATRIX: true
-              DO_DOCS: true
-          - rust: 1.29.0
-            env:
-              DO_FEATURE_MATRIX: true
+        rust: [stable, beta, nightly, 1.29.0]
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v2
@@ -62,6 +50,29 @@ jobs:
         if: matrix.rust == '1.29.0'
         run: cargo generate-lockfile --verbose && cargo update -p cc --precise "1.0.41" --verbose
       - name: Running cargo
-        env: ${{ matrix.env }}
+        env:
+          DO_FEATURE_MATRIX: true
         run: ./contrib/test.sh
 
+  WASM:
+    name: WASM
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust: [stable, beta, nightly] # No 1.29 because WASM requires Rust 1.30
+    steps:
+      - name: Checkout Crate
+        uses: actions/checkout@v2
+      - name: Install clang
+        run: sudo apt-get install -y clang-9
+      - name: Checkout Toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.rust }}
+          override: true
+          components: rust-src
+      - name: Running WASM tests
+        env:
+          DO_WASM: true
+        run: ./contrib/test.sh