First draft of testing guide using RSpec.
Formatting and grammar changes.
Added reference to better specs, and valid use for Factory Girl's 'create' versus 'build_stubbed'. Moved instance initialization portion to Model Spec section.
Added information on single expectation rule, description tense, and naming convention for Factory Girl files.
Changed position of naming conventions within table of contents.
Style and grammar formatting.
Placed Factory Girl and Faker under Helper gems, added bad example for one expectation per example rule.
Merge pull request #47 from ealonas/testing-guide

First draft of testing guide using RSpec.