Improve Makefile.
Improve Makefile.

chris-morgan/rust-http,Shraddha512/rust-http,Shraddha512/rust-http,chris-morgan/rust-http,chris-morgan/rust-http,servo/rust-http,servo/rust-http,Shraddha512/rust-http,chris-morgan/rust-http,Shraddha512/rust-http,servo/rust-http,Shraddha512/rust-http,servo/rust-http