Add Consul v1.7.0-beta2

Specifically not marking as latest here so no one automatically gets this.

library/consul

@@ -1,5 +1,11 @@
 Maintainers: Consul Team <[email protected]> (@hashicorp/consul)
 
+Tags: 1.7.0-beta2, beta
+Architectures: amd64, arm32v6, arm64v8, i386
+GitRepo: https://github.com/hashicorp/docker-consul.git
+GitCommit: 8050b460ae441ba70072f1bf0c50c2cc456338eb
+Directory: 0.X
+
 Tags: 1.6.2, 1.6, latest
 Architectures: amd64, arm32v6, arm64v8, i386
 GitRepo: https://github.com/hashicorp/docker-consul.git