Update to new protobuf and removed workaround for hparams encoding#135

JamieMair wants to merge 10 commits intoJuliaLogging:masterJuliaLogging/TensorBoardLogger.jl:masterfrom

JamieMair:update-to-new-protobufJamieMair/TensorBoardLogger.jl:update-to-new-protobufCopy head branch name to clipboard