esbulk 0.5.0

Get rid of -host and -port flags, see #21.

These missing two flags make this release BACKWARDS INCOMPATIBLE.

Instead of:

$ esbulk -host 10.20.1.2 -port 9201 -index x file.ldj

Use:

$ esbulk -server 10.20.1.2:9201 -index x file.ldj