Updated Composer JSON file.
Added PHP requirement.
Added some Grunt stuff.
Moved class from the Pronamic iDEAL plugin to this library.
Fixed some class names.
Updated badges, added some extra.
Make sure to install the WordPress test suite.
Fix: Fatal error: Class 'Pronamic_Gateways_Sisow_Config' not found.
Added documentation.
Updated Grunt modules.
Exclude a rule.
Improved inline documentation.
Added support for payment methods.
Don't override payment variable.
Filter purchase ID and entrance code to prevent "contains illegal characters" errors.
Require merchant key to sign parameters.
No longer disable SSL verify.
Fixed test.
Exclude "PEAR.Functions.FunctionCallSignature.Indent".
Composer update.