Use single rather than double quotes; use all capitals for constants
Initialise for RSpec

Run rspec --init command.
Make `spec` task available
Add `spec` gem as development dependency
Symbol suggest queries AAPL
Require in spec_helper
Merge branch 'feature/rspec' into develop
Bump to version 0.1.0
Update documentation
Tell Git to ignore .yardoc
Merge branch 'release/0.1.0'