Added custom Marketing Automation activity
Added custom Marketing Automation activity. Added additional package for instances without Web Forms for Marketers (WFFM) module in order to fix the installation errors.
Note: Marketing Automation activity only works in Sitecore 9.0.0 (not 9.0.1 due to https://sitecore.stackexchange.com/questions/10799/custom-marketing-automation-activity-does-not-work-in-sitecore-9-0-1). Sitecore 9.0.1 will be supported in the next version.