Updated `rake init` task to install gems locally in project dir.

Previously, the gems would be installed system-wide.

Signed-off-by: Byron Sanchez <byron@hackbytes.com>
Added travis.yml for CI confiuration specifying a ruby environment

Signed-off-by: Byron Sanchez <byron@hackbytes.com>
Updated README.md

- Added CI status badge
- Updated setup instructions to use the rake init task

Signed-off-by: Byron Sanchez <byron@hackbytes.com>