With the latest 1.1.0 version datastore save returns an 503 error "connect failed"

Downgrading to grpc 1.0.1 in my project seems to fix the issue.

grpc/grpc#9518

Environment details

• OS: ubuntu / appengine nodejs
• Node.js version: 6.9.4
• npm version: 3.10.10
• google-cloud-node version:
  "@google-cloud/datastore": "^0.6.1",
  "@google-cloud/storage": "^0.6.1",

Steps to reproduce

datastore save method returns error