GA release v3.1.2

Changes since v3.1.0: v3.1.0...v3.1.2

Notable changes:

• Using new GitHub Actions CI/CD. Travis builds still working. They will probably be removed once GitHub Actions CI/CD becomes GA and fully available to all.
• graceful master takeover: reduced some overhead; revert to writable on error #948
• Override master promotion: apply post-unsuccessful processes #947
• Include port in DiscoveryIgnoreReplicaHostnameFilters regexp matching, #952 , thanks @dougfales
• Fixing raft leaderAPI URL when URLPrefix nonempty, #951, thanks @xjxyxgq
• support searching by cluster alias #936, thanks @MaxFedotov

sha256sum *.*
6edb952e394e8a6c4dfd91a94ba7bc91918dcc892c41887c86c02eddf50f8c25  orchestrator-3.1.2-1.x86_64.rpm
4abd0f4bddf7dd5899b4acc0f809b89e941c02cddfda5c33e5998def47b69232  orchestrator-3.1.2-linux-amd64.tar.gz
7f951ab76243da1ee1cb2d87e3dd9d59bbe7eaf9b8ad676fce424abc23775636  orchestrator-cli-3.1.2-1.x86_64.rpm
28578833104364cc1e7e59560449c0f33553d34c4248d1dbbf4c5db8e7fddf1c  orchestrator-cli-sysv-3.1.2-1.x86_64.rpm
5de386c02e53f166dfc2971489d4399f3ca0f73a9839dc8cdd5f375548434de7  orchestrator-cli-sysv-3.1.2_amd64.deb
d163ac934c4b3b9f7adf87fab5c4f4fa6c38639b3a2fb0fbdbfbec6d6f0559ce  orchestrator-cli_3.1.2_amd64.deb
fbc9bb0d135306e065d918baf62a0da1236c5b32f997406302cb7ab966bf57fa  orchestrator-client-3.1.2-1.x86_64.rpm
65dc6dbe9f68c04ca9771a1c26a06daef75ea6a7e73ee51a89d2732826faa1eb  orchestrator-client-sysv-3.1.2-1.x86_64.rpm
a84742065902809b3c9eaac29944174b30350f54575c7076baa3bdef2e4d012f  orchestrator-client-sysv-3.1.2_amd64.deb
dc9d35b0d18b431f1a7b92b468b4ac02d30d05706d02e5d88b8be2fe9410cbad  orchestrator-client_3.1.2_amd64.deb
b64274812cb32046a0abd0e3178c2749008e419af3bdd660182255f61e304d73  orchestrator-sysv-3.1.2-1.x86_64.rpm
0bb22c1d85b3608721aa4465f6c94f85f1988f0549697afc89db74a32bc629fe  orchestrator-sysv-3.1.2_amd64.deb
cb66756386466d705f04fe189fb76e83dfa84dc3c5244b091320826aefd0a495  orchestrator_3.1.2_amd64.deb