* ts 2.6

* fix: TransformerFactory type should be SourceFile rather than Node

TypeScript will complain about:
"Type 'Node' is not assignable to type 'SourceFile'."

* fix: use lodash to fix type error

ts.NodeArray now is ReadonlyArray, helper functions should accept
ArrayLike arguments.

* flatten function structure

* fix ts type mismatch

* update test output

* replace helpers.isKind with ts.isXXX

* namespace import lodash & use lodash.find directly

* Use yarn

* travis

* remove hoist transform

* support stateless component

* don't make type alias if prop or state types are empty

* fix: should only transform current source file

* Pretty print using prettier

* Remove yarn log

* Use CLI input for prettier config

* pass config in test

* Add test for defaultProps

* Check if the name == "propTypes", not != " propTypes"

* More ways of getting the class member name (hacky)

* Check if we're an identifier; if we are we can just always use name.escapedText

* Use ts.isIdentifier helper function instead of direct comparison on .kind

* Update dependencies

* Build prettier options only once

* Use a temporary file for the transformation

* Add --ignore-prettier-errors option

* Add --keep-*-files options for easier debugging

* Exit with error code 1 when there were compilation errors

* Fix multiple file/glob parameters

Refs lyft#31

Refs lyft#37

* Add progress message