sip listing and adding a new sip domain
all sip endpoints implemented - golint not run yet
style changes
adding next method to domain list
Merge branch 'master' of https://github.com/natebrennand/twilio-go into sip
Merge branch 'master' of https://github.com/natebrennand/twilio-go into sip
sip now included in account
adding fixtures test
Merge pull request #60 from natebrennand/sip

Sip endpoints finished - golint not run yet