Update .travis.yml file now that Travis-CI supports Rust natively

Author: cosmycoder

.travis.yml

@@ -1,6 +1,2 @@
-install:
-  - curl -O http://static.rust-lang.org/dist/rust-nightly-x86_64-unknown-linux-gnu.tar.gz
-  - tar xfz rust-nightly-x86_64-unknown-linux-gnu.tar.gz
-  - (cd rust-nightly-x86_64-unknown-linux-gnu/ && sudo ./install.sh)
-script:
-  - make check
+language: rust
+script: make check