updated readme
updated readme

- changed crate logo
- added travis badge
- updated tagline

crate/crate,puneetjaiswal/crate,husky-koglhof/crate,adrpar/crate,gmrodrigues/crate,EvilMcJerkface/crate,EvilMcJerkface/crate,crate/crate,crate/crate,adrpar/crate,husky-koglhof/crate,husky-koglhof/crate,gmrodrigues/crate,puneetjaiswal/crate,gmrodrigues/crate,aslanbekirov/crate,EvilMcJerkface/crate,aslanbekirov/crate,puneetjaiswal/crate,adrpar/crate,aslanbekirov/crate