text: Title: Documentation error in allure-robot framework. 
  Body: In MAC, the below command failed with ;. Hence raised this issue.
  
  Need to add : instead of; for custom directory output in robot framework command .
  
  https://github.com/allure-framework/allure-python/blob/master//allure-robotframework/README.rst
  
  In the below command, need to add : instead of ;. 
  
  
  $ robot --listener allure_robotframework;/set/your/path/here  
  
  Same command is also present in pypi url.
  
  https://pypi.org/project/allure-robotframework/ 