Update UnmanagedExports to 1.2.7
Update UnmanagedExports to 1.2.7

Fixes ec6ebd147f468d0bc1831a28ea718cd42cc8f842.

It's not enough to update packages.config, the project also needs to be
updated.

QuantConnect/pythonnet,dmitriyse/pythonnet,dmitriyse/pythonnet,QuantConnect/pythonnet,denfromufa/pythonnet,Konstantin-Posudevskiy/pythonnet,AlexCatarino/pythonnet,vmuriart/pythonnet,dmitriyse/pythonnet,AlexCatarino/pythonnet,pythonnet/pythonnet,yagweb/pythonnet,yagweb/pythonnet,pythonnet/pythonnet,yagweb/pythonnet,Konstantin-Posudevskiy/pythonnet,AlexCatarino/pythonnet,yagweb/pythonnet,vmuriart/pythonnet,vmuriart/pythonnet,Konstantin-Posudevskiy/pythonnet,denfromufa/pythonnet,denfromufa/pythonnet,AlexCatarino/pythonnet,pythonnet/pythonnet,QuantConnect/pythonnet