Integrate SonarCloud

[abitmore]

SonarCloud is a code analysis service. More info: https://about.sonarcloud.io/.

Done: https://sonarcloud.io/dashboard?id=BitShares_Core

[oxarbitrage]

here is the develop branch that was added by @pmconrad already:

https://sonarcloud.io/dashboard?id=BitShares-develop%3Adevelop

i think we should add our our branches master, hardfork, testnet and develop. Also project Bitshares-FC the master branch.

more discussion and assignee is needed.

[pmconrad]

I think it is possible to integrate the sonar scan into automated build processes. The only issue is how to hide the sonar token from external viewers.

[pmconrad]

https://docs.travis-ci.com/user/encryption-keys/
Branch handling can be done better now than what I did - https://docs.sonarqube.org/display/PLUG/Branch+Plugin - master, hardfork, testnet and develop would be "Long lived", everything else short lived. Or sth like that.

[oxarbitrage]

closed by #1081