generous gopher

Concurrent notification sending and a few more API changes.

❯ ./concurrent -c cert.p12 -d {device-token} -n 1000

Time for 1000 notifications: 5.073446529s (5.073446ms ea.)

push

• Send multiple notifications concurrently with Queue. See the README and example/concurrent/ (#54)
• Export NewClient again, as it was in v0.4.x, modify the NewService API.
  • This is more flexible and easier to use from tests.
• Removed the JSON marshalling version of Push and renamed PushBytes to Push.
  • Having queue.Push return errors both before/after queueing felt awkward.
  • Just use json.Marshal instead. This helps clarify that payloads can be serialized once and reused.

This release also contains updates to documentation and examples.