Merge branch 'release/2.5.0' into develop
Bump the min rspec development dependency to 2.13
Merge pull request #215 from sfgeorge/feature/update-min-rspec

Bump the min rspec development dependency to 2.13
[BUGFIX] Ensure DTMF recognisers get shut down when finishing
Update for Guard deprecation
Merge branch 'feature/dtmf_recognizer_leak' into develop
[BUGFIX] Hangup reason on Asterisk was `:hangup`, should be `:hungup`

See [the Rayo spec](http://xmpp.org/extensions/xep-0327.html#def-end-reason)
[UPDATE] Bump to 2.5.1
Merge branch 'release/2.5.1'