Merge pull request #38 from bvssvni/master

Added docs about `GenTextures`
Update Travis CI
Merge pull request #39 from Indiv0/update-travis-ci

Update Travis CI
Add Rust-ci to Travis

Change after_script to after_success
Merge pull request #40 from Indiv0/add-rust-ci-to-travis

Add Rust-ci to Travis
Temporary fix for rust-ci
Merge pull request #41 from Indiv0/fix-rust-ci

Temporary fix for rust-ci
Renamed `clear_shader` to `clear_program`