(chore) Update to a modern travis configuration.

Author: reem

.travis.yml

@@ -1,11 +1,5 @@
-language: c
-env:
-  - LD_LIBRARY_PATH=/usr/local/lib:/usr/local/lib/rustlib/x86_64-unknown-linux-gnu/lib/
-install:
-  - curl https://static.rust-lang.org/rustup.sh | sudo bash
+language: rust
+sudo: false
 script:
-  - cargo build -v
-  - cargo test -v
-  - cargo doc -v
-os:
-  - linux
+  - cargo build
+  - cargo test