Changes/separate mutation

[hrdwdmrbl]

My opinionated v2. Apologies if this is bad, I'm new to graphQL.
Many of the changes are just fixing formatting, etc.
Otherwise I break out Mutation and Nested in to their own classes.
I also renamed filter to select since its usually called the selection filters. Though I do keep an alias for filter

[coveralls]

Coverage decreased (-1.2%) to 98.773% when pulling 2b180c6 on hrdwdmrbl:changes/separate_mutation into 52c12a8 on codemeasandwich:master.