Replace ActiveSupport's Object#to_query with own method

Having ActiveSupport as a dependency seems like overkill for doing
something so simple.
Replace constantize with Object.const_get

There is no point in using a third-party gem, especially ActiveSupport
which depends on everything, for something so simple.
Remove ActiveSupport as a runtime dependency

The two places where ActiveSupport methods were being used have been
modified to no longer require the module.
Merge branch 'technical/remove_active_support'
Remove request stubs from specs
Stub nearby bus stops spec
Revert "Remove request stubs from specs"

This reverts commit b1da8fa09ac3f19f8bbd4f670ef64d92b1b1f4e8.
Stub nearby bus stop requests inside spec
Add Rake tasks for Cucumber and RSpec
Add Cucumber env.rb
Add ruby version file with 2.1.5 specified
Add cucumber tests with usage instructions from README
Isolate BusStop live departures spec