Update license year / license holders

This plugin's repo layout was based upon
https://github.com/prettier/eslint-plugin-prettier and the original
licence holders were set to reflect that initial base, however almost
none of the original codebase remains. Having Andres and Teddy as license
holders does not reflect that reality, so remove them.

LICENSE.md

@@ -1,6 +1,6 @@
 # The MIT License (MIT)
 
-Copyright © 2017 Ben Scott, Andres Suarez and Teddy Katz
+Copyright © 2018 Ben Scott
 
 Permission is hereby granted, free of charge, to any person
 obtaining a copy of this software and associated documentation