Upgrade to rbt 0.7.4.
Upgrade to rbt 0.7.4.

Reviewed at https://reviews.apache.org/r/36100/

rosmo/aurora,mschenck/aurora,wfarner/aurora,rosmo/aurora,rdelval/aurora,protochron/aurora,crashlytics/aurora,shahankhatch/aurora,thinker0/aurora,shahankhatch/aurora,thinker0/aurora,protochron/aurora,medallia/aurora,rdelval/aurora,shahankhatch/aurora,crashlytics/aurora,apache/aurora,crashlytics/aurora,kidaa/aurora,protochron/aurora,medallia/aurora,shahankhatch/aurora,rosmo/aurora,kidaa/aurora,apache/aurora,wfarner/aurora,thinker0/aurora,wfarner/aurora,apache/aurora,rdelval/aurora,apache/aurora,mschenck/aurora,wfarner/aurora,thinker0/aurora,mschenck/aurora,kidaa/aurora,shahankhatch/aurora,kidaa/aurora,protochron/aurora,medallia/aurora,rosmo/aurora,protochron/aurora,rosmo/aurora,medallia/aurora,kidaa/aurora,apache/aurora,wfarner/aurora,thinker0/aurora,rosmo/aurora,wfarner/aurora,mschenck/aurora,protochron/aurora,apache/aurora,kidaa/aurora,medallia/aurora,medallia/aurora,thinker0/aurora,crashlytics/aurora,crashlytics/aurora,mschenck/aurora,rdelval/aurora,rdelval/aurora,rdelval/aurora,shahankhatch/aurora,crashlytics/aurora,mschenck/aurora