add rake to gemfile for heroku
dont do shitty macosx stuff based on broken homebrew package

remove text cleaning that was actually to address the janky version of
pdftotext packeged with xpdf on homebrew macosx, but if you use the
REAL version from the poppler package, macosx acts just like linux,
sigh.

this is why you use the same OS in dev and production, urgh.