Smarter answer validation 

#### What's this PR do?
Uses regex to be a little more flexible with validating correct answers. For example, we want to allow an answer of 'A)' or 'A.' even if our `valid_answers` array in the config file only has 'A'.

#### What are the relevant tickets?
Issue DS-174
This might also be a good place to think about adding some "machine learning" where an invalid response could respond with a "Didi you mean A? If so type A again?" when we get q,w,s,x or z (all keys around "a". Recording the correct response vs the invalid response will allow us to make a "guess" that eventually might not need a second question. Ex. 99% of "z" are actually "a".

Just dreaming...