Display some version information at the startup

[Rader]

I run into this issue - Rpc error: unknown service graphp.Dgraph -after I run dgraph from the command line. Finally I found and old version 0.7.3 is launched, instead of the latest build of Dgraph.

So I am thinking why don't we display some version information at the startup, so that we know we are running the right version of Dgraph?

[pawanrawal]

This has been merged to master and the next release would contain this.