chore(ci): check all feature combinations in CI

.github/workflows/CI.yml

@@ -9,6 +9,17 @@ env:
   RUST_BACKTRACE: 1
 
 jobs:
+  ci-pass:
+    name: CI is green
+    runs-on: ubuntu-latest
+    needs:
+      - style
+      - test
+      - features
+      - doc
+    steps:
+      - run: exit 0
+
   style:
     name: Check Style
     runs-on: ubuntu-latest
@@ -82,17 +93,9 @@ jobs:
           args: --benches ${{ matrix.features }}
 
   features:
-    name: Test Feature ${{ matrix.features }}
+    name: features
     needs: [style]
-    strategy:
-      matrix:
-        features:
-          - "--features __internal_happy_eyeballs_tests"
-          - "--no-default-features --features tcp"
-          - "--no-default-features"
-
     runs-on: ubuntu-latest
-
     steps:
       - name: Checkout
         uses: actions/checkout@v1
@@ -101,14 +104,14 @@ jobs:
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: stable
+          toolchain: nightly
           override: true
 
-      - name: Test
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: ${{ matrix.features }}
+      - name: Install cargo-hack
+        run: cargo install cargo-hack
+
+      - name: check --each-feature
+        run: cargo hack check --each-feature -Z avoid-dev-deps
 
   doc:
     name: Build docs