Removed CONTRIBUTING file and updated license
Removed CONTRIBUTING file and updated license

Original commit: elastic/x-pack-elasticsearch@70a8079d3b71f9d4f97e8f2b8a5f7da20def25d9

scorpionvicky/elasticsearch,coding0011/elasticsearch,gingerwizard/elasticsearch,gfyoung/elasticsearch,scorpionvicky/elasticsearch,scorpionvicky/elasticsearch,gfyoung/elasticsearch,uschindler/elasticsearch,robin13/elasticsearch,vroyer/elassandra,uschindler/elasticsearch,GlenRSmith/elasticsearch,nknize/elasticsearch,strapdata/elassandra,coding0011/elasticsearch,strapdata/elassandra,HonzaKral/elasticsearch,gingerwizard/elasticsearch,coding0011/elasticsearch,nknize/elasticsearch,scorpionvicky/elasticsearch,gingerwizard/elasticsearch,gfyoung/elasticsearch,GlenRSmith/elasticsearch,strapdata/elassandra,vroyer/elassandra,uschindler/elasticsearch,nknize/elasticsearch,HonzaKral/elasticsearch,gfyoung/elasticsearch,gingerwizard/elasticsearch,gingerwizard/elasticsearch,robin13/elasticsearch,uschindler/elasticsearch,gingerwizard/elasticsearch,GlenRSmith/elasticsearch,uschindler/elasticsearch,robin13/elasticsearch,nknize/elasticsearch,robin13/elasticsearch,strapdata/elassandra,HonzaKral/elasticsearch,GlenRSmith/elasticsearch,HonzaKral/elasticsearch,coding0011/elasticsearch,GlenRSmith/elasticsearch,scorpionvicky/elasticsearch,robin13/elasticsearch,coding0011/elasticsearch,strapdata/elassandra,gingerwizard/elasticsearch,nknize/elasticsearch,vroyer/elassandra,gfyoung/elasticsearch