Working on cl-ngxmpp-client's high api.

IOLib (iolib-adapter.lisp as well) was temporarily removed from dependencies.
handle-stanza methods become deprecated from now, because high api
exist.
Added nicknames for cl-ngxmpp, and cl-ngxmpp-client - xmpp%, and xmpp.
Added alexandria to dependencies.
Added test stanza testcase for CI.
Added .travis.yml to try out travic CI in action.
Merge branch 'feature-client-high'