Fixing exp timestamp in capability token.
use https instead of http for the GET test
Create TwilioMessage.cls
Create TwilioMessageList.cls
Create TwilioMedia.cls
Create TwilioMediaList.cls
Update TwilioIterator.cls
Update TwilioAccount.cls
Added messages and media resources
Added messages and media
Added Test classes
modified package.xml file
modified package.xml
Merge branch 'use-https-for-tests' of github.com:brettgerry/twilio-salesforce into update-headers
Fixing exp timestamp in capability token.
add Accept-Charset header and update version and agent
merge capability token timestamp fix
Merge pull request #27 from brettgerry/messages-support

Support for new Messages resource (MMS and Media)
Merge pull request #28 from brettgerry/update-headers

Update headers for requests and fix capability token exp timestamp