Bump version number to 0.5.0
Bump version number to 0.5.0

Reviewed at https://reviews.apache.org/r/16673/

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