context: check given path is absolute path in constructor (issue #30)
travis: use version string (issue #29)

* e.g. 2.1 => "2.1"
context: spec: use expect instead of subject/should (issue #28)
base_repository: test: remove `#` character (issue #23)
tag_parser: test: improve context names (issue #15)
tag: fix typos (issue #12, #13)
tag: test: fix typo (issue #11)
change `func()` => `func`

* run :%s;\([a-z_?]*\)();\1;