fix: __new__ тут не нужен
fix addSMS: send_datetime can be instance of datetime.datetime
fix: old test phone number returns 213 error from SMSPilot
add: send_datetime test
fix: pep8
fix: statify checks
add: ttl
add: callback url support
misc: version 1.3
fix: readme
fix: markdown
fix: markdown
Merge pull request #7 from bevice/master

Merging contribution by bevice.