README.md's link to ClusterIT.java is busted

[sming]

See https://github.com/spotify/heroic/blob/master/rpc/jvm/README.md :

For an example of this, see the ClusterIT test suite.

The link is to https://github.com/spotify/heroic/blob/master/heroic-dist/src/test/java/com/spotify/heroic/ClusterIT.java which is nonexistant.

[sming]

@sjoeboo, any idea which file it should point to? perhaps https://github.com/spotify/heroic/blob/master/heroic-dist/src/test/java/com/spotify/heroic/AbstractLocalClusterIT.java ?

[lmuhlha]

Yup should be the latter, I made a PR: https://github.com/spotify/heroic/pull/672/