streamchain

The TestRestartAfterCheckpoint test exhibits intermittent failures which
is causing problems in CI and erroneously flagging builds as failed
which should otherwise pass.  This changeset disables that test until a
more permanent solution can be found.

This is related to, (though does not resolve) JIRA issue:

https://jira.hyperledger.org/browse/FAB-624



Change-Id: Ic583758130218104f78b6b5bcc439dcfbc6339df
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>