v1.6.0 RobBot

• Some refactoring done in #112 #113 #115
• Add /eq command to get recently earthquake data in #116
• Update of /ai command. Added /aimg command and builded a credit system for users. #117
• Update /atm command by giving time table as image when needed. #118

#87 is still the only one little problem as said since the release 1.2.0