Remove rspec-instafail from the project

Conflicts:
	fuubar.gemspec
Remove all references to instafail

Conflicts:
	lib/fuubar.rb
Use RSpec's helpers to output the failures at the proper time
Add .ruby-version file
Big refactoring to use the capabilities exposed by RSpec's formatters as well as replacing the specs with ones which are more representative
Merge branch 'feature/remove-rspec-instafail' into develop - Closes #36, #29, #20, #33

* feature/remove-rspec-instafail:
  Big refactoring to use the capabilities exposed by RSpec's formatters as well as replacing the specs with ones which are more representative
  Add .ruby-version file
  Use RSpec's helpers to output the failures at the proper time
  Remove all references to instafail
  Remove rspec-instafail from the project