Create a general Logging system for PyBot activity

[raamink]

Such an enhancement would be helpful for two main reasons.

1. Logging questions and answers for later analysis (for FAQ for example)
2. Automatically populating a list with students who have turned in their assignemnt as well as their grade

As such the requirements for the Logging system are:

• Ability to log metadata for issued commands such as User, command tag, message, and current status (answered/unanswered & submitted/passed/failed etc.). See Issue Support reaction-based input system for setting the state of a question/answer  #5 for the implementation of using reactions to determine the state of a question/answer.

• Creating an Excel or alternative datafile containing the status of submitted assignments