Add MechanicalSoup to project's requirements
Add MechanicalSoup to project's requirements

(because mechanize doesn't support Python3)

openaid-IATI/OIPA,zimmerman-zimmerman/OIPA,zimmerman-zimmerman/OIPA,openaid-IATI/OIPA,zimmerman-zimmerman/OIPA,openaid-IATI/OIPA,openaid-IATI/OIPA,zimmerman-zimmerman/OIPA,openaid-IATI/OIPA,zimmerman-zimmerman/OIPA