Bump the revision of mmtk-core and ruby repos #137

Job	Run time
Style check	1m 10s
Style check	1m 10s
Build and test (debug, MarkSweep)	9m 5s
Build and test (debug, MarkSweep)	8m 56s
Build and test (debug, Immix)	7m 45s
Build and test (debug, Immix)	7m 45s
Build and test (debug, StickyImmix)	4m 15s
Build and test (debug, StickyImmix)	4m 15s
Build and test (release, MarkSweep)	9m 22s
Build and test (release, MarkSweep)	9m 13s
Build and test (release, Immix)	9m 21s
Build and test (release, Immix)	9m 11s
Build and test (release, StickyImmix)	6m 54s
Build and test (release, StickyImmix)	6m 54s
Build and test (vanilla)	4m 26s
Build and test (vanilla)	4m 26s
	1h 44m 8s

Provide feedback