* Let Jest handle all file types

* Update regexes

* Fix exclusion regex to also exclude files without extension
* Be over-cautious with Windows paths because I'm not sure how Jest handles them

* There is no automatic babel-jest discovery now that we use transsform

tagging dev-only code (@remove-on-publish-begin/end) and pre-eject-only code (@remove-on-eject-begin/end) #257 (#257)