timer: finish updating timer (#1222)

* timer: restructure feature flags
* update timer tests
* Add `async-traits` to CI

This also disables a buggy `threadpool` test. This test should be fixed in the future.

Refs #1225

ci/azure-test-stable.yml

@@ -34,9 +34,12 @@ jobs:
   - template: azure-patch-crates.yml
 
   - ${{ each crate in parameters.crates }}:
-    - script: cargo test --lib && cargo test --tests && cargo test --examples
-      env:
-        LOOM_MAX_DURATION: 10
-        CI: 'True'
-      displayName: cargo test -p ${{ crate }} (PATCHED)
-      workingDirectory: $(Build.SourcesDirectory)/${{ crate }}
+    - ${{ each feature in crate.value }}:
+      - script: cargo test --tests --no-default-features --features ${{ feature }}
+        env:
+          LOOM_MAX_DURATION: 10
+          CI: 'True'
+        displayName: cargo test --tests --features ${{ feature }}
+
+      - script: cargo test --examples --no-default-features --features ${{ feature }}
+        displayName: cargo test --examples --features ${{ feature }}