Call stop before raising SocketError in _read_loop

[agberk]

I've moved the socket cleanup code into stop and called it before raising SocketError.

I had to modify one of the tests since it was expecting a SocketError but the stop code was causing a different exception to be thrown as the socket was mocked and it was trying to call a non-existent method.

Maybe it would have been better to mock the shutdown and close methods on the socket instead?

[coveralls]

Coverage increased (+0.005%) to 95.149% when pulling 543befa on agberk:issue-45 into 0563477 on liampauling:master.

[liampauling]

Sorry for the delay but how about the following to keep things DRY

except (socket.timeout, socket.error) as e:
    self.stop()
    raise SocketError('[Connect: %s]: Socket %s' % (self.unique_id, e))

[agberk]

Yup sounds sensible - I'll add another commit.

[coveralls]

Coverage decreased (-0.002%) to 95.142% when pulling b82d36b on agberk:issue-45 into 0563477 on liampauling:master.