Fixing all RSpec deprecation warnings

I turned on `raise_errors_for_deprecations!` in 
`spec\spec_helper.rb`, that helped me track down
all deprecation warnings. I fixed all of them, 
left this setting in the spec_helper file to enforce
the new RSpec syntax going forward.
Merge pull request #12 from adomokos/fix-all-rspec-deprecation-warnings

Fixing all RSpec deprecation warnings