Autoselect ephemeral port if none specified.
Autoselect ephemeral port if none specified.

Closes #24.

JonyEpsilon/gorilla-repl,gorillalabs/gorilla-repl,mrcslws/gorilla-repl,deas/gorilla-notebook,deas/gorilla-notebook,gorillalabs/gorilla-repl,deas/gorilla-notebook,deas/gorilla-notebook,mrcslws/gorilla-repl,JonyEpsilon/gorilla-repl