Update README.md
Merge pull request #6 from heitortsergent/master

Updated lib to be more similar with other languages
Adding podspec, updating to 0.2.0
minor spelling correction
Fixes #5, only require html or text parameter
Merge branch 'master' of https://github.com/sendgrid/sendgrid-objc
Release 0.2.1
Fixes #10, setting only 'setTos' array doesn't break the app
Release 0.2.2
fixed README conflict
Merge branch 'sendgrid-master'
fixed error exception when only to was set
Release 0.2.3
Merge pull request #1 from sendgrid/master

Updating