Revert "send encoding in headers"

This reverts commit 34021d15bc02c8daec7db191a1d7a97800d0abaa.
don't persist threadlocal through specs
ignore some style warnings
add rubocop
depend on activesuport
Update request schema within test suite
Merge pull request #62 from Strech/multitest_for_single_endpoint

Request schema updating in single test suite
generate proper Gemfile for developers
Revert "depend on activesuport"

This reverts commit a0f9bfdd3cfe34e65fb26f71913b983bc564694a.
weaken pdfkit dep
weaken hashie dep
weaken execjs dep
weaken kramdown dep
weaken diffy dep
weaken pdfkit dep
weaken execjs dep
add certs
revert deps as development for tests
depend on activesupport
fix duplicate dependency