[feature] login,registration,share,search moods
new exception for wrong api key
file helper for user photos
change some http response codes
[minor] some changes in the unregistration process
[tests] new mocha version
[minor] typo in environment variables
[minor] dry user login and unregistration
refactor file helper for user photos
new exceptions for searching moods
[minor] mood search verification, mood is identified by username
trim whitespaces
[minor] file helper reads user's photo file
move mongo connection to configuration, remove authentication for user's photo
[issue #2,#4,#5], mongodb expireAfter mecanism for moods
[issue #2,#4,#5], mongodb expireAfter mecanism for moods
[issue #6]
check errors in mongodb connection
expire moods after 24hours
change apikey header to X-API-Key