add mixunit to Testing
add Security category + add safetybox to it
add exgenius to Third Party APIs
add xoauth2 to Authentication
add qiita_ex to Third Party APIs
add keenex to Third Party APIs
add stripe to Third Party APIs
add curtail to Text and Numbers
add dye to Miscellaneous
reoder lines
add exlingr to Third Party APIs
add exelli to Frameworks
add pattern_tap to Macros
add exkad to Algorithms and Datastructures
add mandrillex to Third Party APIs
tweak .travis.yml and update used otp_release
downgrade to 17.1 for now

because of a known bug in Erlang OTP 17.3 (http://stackoverflow.com/questions/26090500/elixir-problems-with-https-urls)
Merge pull request #214 from optikfluffel/master

add oauth2ex to Authentication category
Merge pull request #215 from optikfluffel/mixunit

add mixunit to Testing
Merge pull request #216 from optikfluffel/safetybox

add Security category + add safetybox to it