Merge pull request #6 from opinali/master

OpenRtbUtils.filterBids() updated to use Bid.Builder instead of Bid
[maven-release-plugin] prepare release 0.7.0
[maven-release-plugin] prepare for next development iteration
Protobuf 2.6.0
[maven-release-plugin] prepare release 0.7.1
[maven-release-plugin] prepare for next development iteration