[core] restructure to allow PIP packaging

OK - so I have to admit I *hate* the fact that PIP seems to require a
subdirectory named like the library.

But since the PIP package is something really nifty to have (thanks to
@tony again!!!), I updated the codebase to hopefully conform with what
PIP expects. Testruns so far look promising...

bumblebee_status/modules/contrib/docker_ps.py

@@ -0,0 +1,48 @@
+# -*- coding: utf-8 -*-
+
+"""Displays the number of docker containers running
+
+Requires the following python packages:
+    * docker
+
+contributed by `jlopezzarza <https://github.com/jlopezzarza>`_ - many thanks!
+"""
+
+import docker
+
+from requests.exceptions import ConnectionError
+
+import core.module
+import core.widget
+import core.decorators
+
+
+class Module(core.module.Module):
+    @core.decorators.every(seconds=5)
+    def __init__(self, config, theme):
+        super().__init__(config, theme, core.widget.Widget(self.docker_info))
+        self.__info = ""
+
+    def state(self, widget):
+        state = []
+        if self.__info == "OK - 0":
+            state.append("warning")
+        elif self.__info in ["n/a", "off"]:
+            state.append("critical")
+        return state
+
+    def docker_info(self, widget):
+        try:
+            cli = docker.DockerClient(base_url="unix://var/run/docker.sock")
+            cli.ping()
+            self.__info = "OK - {}".format(
+                len(cli.containers.list(filters={"status": "running"}))
+            )
+        except ConnectionError:
+            self.__info = "off"
+        except Exception:
+            self.__info = "n/a"
+        return self.__info
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4