Added spec for pot
Updated travis bundle install

Travis wasn't installing test gems as it does a bundle install
--deployment. Hoping that switching to a normal bundle install will fix
this.
Removed un-needed require

The components are required in lib/pedalboard so there is no need for
the spec to require it.
Switched from using const_get to eval

Was having issues dynamically creating components on Travis. Suspected
it was due to using Object.const_get to get the component classes.
Switching to use eval resolved the issue.
Added code climate test coverage

Added code climate test coverage reporting.
Converted to use device class

The way the app is currently structured means that all classes are
created as inner classes of the Pedalboard class whereas usually
everything would be encapsulated in a module. As the first part of
moving towards a more standard structure, the class-like behaviour of
the Pedalboard has been moved into a Device class making it easier to
change the remaining Pedalboard class to a module.
Converted Pedalboard to a module

In order to give the application a more standard structure, the
Pedalboard class has been converted to a module.