add "See also" section to README
spelling in README
update sbt-revolver to 0.7.2
update akka and spray
Merge pull request #61 from cvrebert/spray-updates

update akka and spray
update spray-json to 1.3.1
Merge pull request #62 from cvrebert/update-spray-json

update spray-json to 1.3.1
Fixes #59
update twitter-text to 1.9.9
Merge pull request #63 from cvrebert/twitter-text-1.9.9

update twitter-text to 1.9.9
add optional Bootlint integration; fixes #58