Fixed LogProtector test failures
Fixed LogProtector test failures

Other tests potentially leave around junk in
LogProtector::epochProviders. Fixed LogProtectorTest
to remove this, if present.

anirajk/RAMCloud,utah-scs/RAMCloud,anirajk/RAMCloud,utah-scs/RAMCloud,SMatsushi/RAMCloud,anirajk/RAMCloud,anirajk/RAMCloud,jblomer/ramcloud,jblomer/ramcloud,jblomer/ramcloud,SMatsushi/RAMCloud,anirajk/RAMCloud,SMatsushi/RAMCloud,utah-scs/RAMCloud,utah-scs/RAMCloud,SMatsushi/RAMCloud,utah-scs/RAMCloud,jblomer/ramcloud,SMatsushi/RAMCloud,utah-scs/RAMCloud,jblomer/ramcloud,jblomer/ramcloud,SMatsushi/RAMCloud,anirajk/RAMCloud