Update mechs.groovy
Update mechs.groovy

Added self-upgrading card Upgrado Mk I through Mk 5
SirPython/Cardshifter,Cardshifter/Cardshifter,SirPython/Cardshifter,June92/Cardshifter,June92/Cardshifter,June92/Cardshifter,Cardshifter/Cardshifter,Cardshifter/Cardshifter,SirPython/Cardshifter