Update to build in no_std mode on latest Rust nightly

Author: mbrubeck

.travis.yml

@@ -6,7 +6,7 @@ rust:
 script: |
   cargo build --verbose &&
   cargo test --verbose &&
-  ([ $TRAVIS_RUST_VERSION != nightly ] || cargo test --verbose --no-default-features) &&
+  ([ $TRAVIS_RUST_VERSION != nightly ] || cargo check --verbose --no-default-features) &&
   ([ $TRAVIS_RUST_VERSION != nightly ] || cargo test --verbose --features union) &&
   ([ $TRAVIS_RUST_VERSION != nightly ] || cargo bench --verbose bench)
 notifications:

lib.rs

@@ -39,7 +39,7 @@
 extern crate alloc;
 
 #[cfg(not(feature = "std"))]
-use alloc::Vec;
+use alloc::vec::Vec;
 
 #[cfg(feature = "serde")]
 extern crate serde;