copy edits [ci skip]

guides/source/development_dependencies_install.md

@@ -24,7 +24,7 @@ Ruby on Rails uses Git for source code control. The [Git homepage](http://git-sc
 * [Try Git course](http://try.github.io/) is an interactive course that will teach you the basics.
 * The [official Documentation](http://git-scm.com/documentation) is pretty comprehensive and also contains some videos with the basics of Git
 * [Everyday Git](http://schacon.github.io/git/everyday.html) will teach you just enough about Git to get by.
-* The [PeepCode screencast](https://peepcode.com/products/git) on Git ($12) is easier to follow.
+* The [PeepCode screencast](https://peepcode.com/products/git) on Git is easier to follow.
 * [GitHub](http://help.github.com) offers links to a variety of Git resources.
 * [Pro Git](http://git-scm.com/book) is an entire book about Git with a Creative Commons license.
 

guides/source/testing.md

@@ -372,7 +372,7 @@ Here's an extract of the assertions you can use with `minitest`, the default tes
 | `assert_raises( exception1, exception2, ... ) { block }`         | Ensures that the given block raises one of the given exceptions.|
 | `assert_nothing_raised( exception1, exception2, ... ) { block }` | Ensures that the given block doesn't raise one of the given exceptions.|
 | `assert_instance_of( class, obj, [msg] )`                        | Ensures that `obj` is an instance of `class`.|
-| `refute_instance_of( class, obj, [msg] )`                       | Ensures that `obj` is not an instance of `class`.|
+| `refute_instance_of( class, obj, [msg] )`                        | Ensures that `obj` is not an instance of `class`.|
 | `assert_kind_of( class, obj, [msg] )`                            | Ensures that `obj` is or descends from `class`.|
 | `refute_kind_of( class, obj, [msg] )`                            | Ensures that `obj` is not an instance of `class` and is not descending from it.|
 | `assert_respond_to( obj, symbol, [msg] )`                        | Ensures that `obj` responds to `symbol`.|