version to 2.5.0

* assert true/false assertions (#177)
* cleanups/standardizations to assertion fail messages (#176)
* use diff output in `assert_same` assertion fail messages (#174)
* only display ANSI styled output if the view IO is a tty (#173)
* `suite` DSL method on context classes (#171)
* show tests-per-sec and resuls-per-sec in views (#170)
* formally configure the test file suffixes (#169)
* move the git changed proc from a const to a defined util (#168)
* use `ENV['HOME']` as the root for looking up custom views (945dc63a569d17f47b07473ac85a76076b213483)
* cleanup the old `class << self` method of adding context DSL methods (#167)
* non-singleton Config class (#166)
* rename `changed_files` config setting to `changed_proc` (#165)
* `Factory.test` now takes "flexible" args (#161)
* remove superfulous newlines from diff/pp output (#158)

/cc @jcredding