Revert "Use make commands on Travis CI."
Revert "Use make commands on Travis CI."

This reverts commit 43b0d21f98238df282159347e8b6d4ee329853de.

zsiciarz/rust-ffi-stringtools,zsiciarz/rust-ffi-stringtools,zsiciarz/rust-ffi-stringtools,zsiciarz/rust-ffi-stringtools,zsiciarz/rust-ffi-stringtools,zsiciarz/rust-ffi-stringtools,zsiciarz/rust-ffi-stringtools