PROTON-2154: update versions for 0.31.0-rc2
PROTON-2154: update versions for 0.31.0-rc2

ssorj/qpid-proton,apache/qpid-proton,gemmellr/qpid-proton,apache/qpid-proton,ssorj/qpid-proton,gemmellr/qpid-proton,ChugR/qpid-proton,ChugR/qpid-proton,apache/qpid-proton,astitcher/qpid-proton,ChugR/qpid-proton,ChugR/qpid-proton,ssorj/qpid-proton,apache/qpid-proton,ssorj/qpid-proton,apache/qpid-proton,astitcher/qpid-proton,astitcher/qpid-proton,gemmellr/qpid-proton,ssorj/qpid-proton,ChugR/qpid-proton,ChugR/qpid-proton,apache/qpid-proton,gemmellr/qpid-proton,gemmellr/qpid-proton,gemmellr/qpid-proton,astitcher/qpid-proton,ssorj/qpid-proton,astitcher/qpid-proton,astitcher/qpid-proton