Allow bundle:install to skip having shared bundle paths if bundle_path is set to nil.
Allow bundle:install to skip having shared bundle paths if bundle_path is set to nil.

ianks/mina,chip/mina,scalp42/mina,flowerett/mina,estum/mina,estum/mina,dcalixto/mina,dcalixto/mina,flowerett/mina,allantatter/mina,openaustralia/mina,cyberwolfru/mina,Zhomart/mina,scalp42/mina,whhx/mina,whhx/mina,allantatter/mina,mfinelli/mina,ianks/mina,stereodenis/mina,cyberwolfru/mina,mfinelli/mina,Zhomart/mina,openaustralia/mina