Merge pull request #4 from adamaltman/master

updated readme with installation, usage, requirements, documentation and...
Merge pull request #5 from adamaltman/master

adjust metered billing and three d secure endpoints and added test
Update RebillySubscription.php
Merge pull request #1 from Rebilly/master

Merge PR
Add docblock and const
Add const and docblock
small comments fix
Merge pull request #6 from dara123/master

Use const and Add docblock
Add http response code
Merge pull request #7 from dara123/master

Add http response code
Add custom field
Add new line
Use array format
Merge pull request #8 from dara123/master

Add custom field
Add setAttributes()
Merge pull request #9 from dara123/master

Add setAttributes()
remove staging and dev URL
Add const ENV_LIVE
Add comment
Merge pull request #10 from dara123/master

remove staging and dev URL