Update setup.py and README for PyPI release

Author: johnsca

README.md

@@ -13,8 +13,7 @@ Include this library as a dependency for your charm, either in
 reactive charms:
 
 ```
-# TODO: publish this to PyPI
-https://github.com/juju-solutions/loadbalancer-interface/archive/master.zip#egg=loadbalancer_interface
+loadbalancer_interface
 ```
 
 ## Usage

setup.py

@@ -12,10 +12,7 @@
         "ops>=1.0.0",
         "cached_property",
         "marshmallow",
-    ],
-    # TODO: move this to normal PyPI dependency when ready
-    "dependency_links": [
-        "https://github.com/juju-solutions/ops-reactive-interface/archive/master.zip#egg=ops-reactive-interface",  # noqa
+        "ops_reactive_interface",
     ],
     "entry_points": {
         "ops_reactive_interface.provides": "loadbalancer = loadbalancer_interface:LBProducer",  # noqa