Create a dictionary of varied responses

[Geit]

Currently Alexa always responds with the exact same phrase for a given input, we should try and define a large dictionary of phrases with equivilent meaning that Alexa can then pick from at random. This would help Alexa to feel more like a real person, rather than just a robot.

[Geit]

I've commited a change that implements this functionality, but I haven't yet populated the dictionary with many possible responses (see translations/en-gb.js) - It'd be a massive help if someone jumped in and add some variations where possible.

I also didn't implement the functionality on the targets responses, as they are somewhat more complicated than the others. I will probably look into doing them in another issue.