Implement all of the current stream request test cases in pyupr

Send Stream request (No open connection)

1. Send a stream request message (Don’t send an open connection command)
2. Check to see if the connection was closed

Send stream request (Wrong connection type)

1. Send an open connection for a consumer
2. Send a stream request message
3. Check to see if the client is disconnected
4. Send stream request

Send open connection for a producer

1. Send a stream request (start seqno = 0, end seqno = 0, vb uuid = 0, high seqno = 0)
2. Expect to get an ok message followed by a stream end message

Send stream request for non-existent vbucket

1. Send open connection for producer
2. Send a stream request for vbucket 1025 and expect a not my vbucket error

Send two stream requests for the same vbucket

1. Send an open connection for producer
2. Send a stream request for and specify the end sequence number as 100
3. Verify that this stream has been succesfully created by checking the stats
4. Send another stream request for the same vbucket and expect and EXISTS error
5. Check the upr stats again and make sure that the initial stream still exists.