Remove no-default-features test since it's not working

.azure-pipelines.yml

@@ -43,14 +43,8 @@ stages:
             displayName: Cache cargo
           - script: rustup default $(rust)-$(target)
             displayName: Install rust
-          - script: cargo test --no-default-features
-            displayName: Test without default features
-            env:
-              RUST_BACKTRACE: full
           - script: cargo test --features "yaml unstable"
             displayName: Test with most features
-            env:
-              RUST_BACKTRACE: full
           - script: |
               rmdir /Q /S C:\Rust\.cargo\registry\src
             displayName: Cleanup cache

.travis.yml

@@ -58,8 +58,7 @@ jobs:
       script:
         - cargo tarpaulin --workspace --features "yaml unstable" --ciserver travis-ci --coveralls $TRAVIS_JOB_ID
 script:
-  - cargo test --no-default-features
-  - cargo test --features yaml unstable
+  - cargo test --features "yaml unstable"
 notifications:
   email: false
 env:

CONTRIBUTING.md

@@ -9,7 +9,6 @@ Another really great way to help is if you find an interesting, or helpful way i
 To test with all features both enabled and disabled, you can run these commands:
 
 ```sh
-$ cargo test --no-default-features
 $ cargo test --features "yaml unstable"
 ```