v3.1.0

Empire 3.1.0
- Added Multi-user Collaboration to API - #105 (@Cx01N & @vinnybod)
- Updated to Mimikatz 2.2.0 20200208 - #104 (@Cx01N)
- Fixed incorrect header on python response packet (@Cx01N)
- Added progress bar to download function - #106 (@Cx01N)
- Expanded API functionality (@vinnybod)
- Fixed str/byte in empire.py - #103 (@hypnoticpattern)
- Fixed typos in helpers.py - #103 (@hypnoticpattern)
- Fixed unsupported formatting for null hostname - #103 (@hypnoticpattern)
- Added function name aliasing to Invoke-Empire & Mimikatz - #109 (@Hubbl3)