Merge branch 'release/v0.1.1' into develop
Removed an extra require line from rbtclk.rb.
Implemented a function that shows version of rbtclk.
Implemented color option feature.
Change an way to terminate rbtclk in Countup.
Added some spec files.
Modifed README.md.
v0.2.0
Merge branch 'release/v0.2.0'