Simplify grpc build instructions. (#171)
Simplify grpc build instructions. (#171)

Since electron support went into grpc we no longer need
to use a special branch or build instructions.

Until there is a new GRPC release local building is still necessary.

Closes #170
decred/decrediton,decred/decrediton,decred/decrediton,oktapodia/decrediton-appveyor-test,decred/decrediton,oktapodia/decrediton-appveyor-test,decred/decrediton,oktapodia/decrediton-appveyor-test,oktapodia/decrediton-appveyor-test,oktapodia/decrediton-appveyor-test,decred/decrediton