Merge pull request #585 from bvssvni/master

Added build script
Merge pull request #588 from bvssvni/master

Using Cargo for Travis CI build
Use rustup to handle installation for travis

rustup now installs both the latest rust nightly and cargo,
so we no longer need to manually manage the installation process
for cargo or rust.
Merge pull request #589 from reem/travis-use-rustup

Use rustup to handle installation for travis
Ignore Cargo.lock