Added subprotocol header.
Merge pull request #5 from voryx/master

Added subprotocol header.
fixed typo in InvalidArgumentException name
Merge pull request #6 from voryx/master

fixed typo in InvalidArgumentException name
Enforce sub-protocol checks. fixes #4

Fail the connection as per 4.1 of the spec if the server responds with a protocol not asked for by the client.

Also failing if the server does not respond with a protocol that was asked for. This is not defined by the spec but is valid.

This is an opinionated implementation.
Merge branch 'master' into ab-tests

# By Chris Boden (1) and others
# Via Chris Boden
* master:
  Enforce sub-protocol checks. fixes #4
  fixed typo in InvalidArgumentException name
  Added subprotocol header.
autobahn tests 2.*