Merge pull request #14 from fassn/master

allows for use with guzzlehttp/guzzle

Merge pull request #17 from AurelC2G/global_lending_history

Added support for getting the global lending history

Added endpoint for withdrawal fees

Merge pull request #11 from AurelC2G/submit_lending

Added support for submitting lending offers

Merge pull request #10 from AurelC2G/market_orders

Fixed market orders

Fix for missing return #6

Run GH action with PHP 7.4

Updated README

Added rate limit exception