set version using setuptools_scm

Author: kotfu

cmd2_myplugin/__init__.py

@@ -5,4 +5,11 @@
 An overview of what myplugin does.
 """
 
+from pkg_resources import get_distribution, DistributionNotFound
+
 from .myplugin import empty_decorator, MyPlugin
+
+try:
+    __version__ = get_distribution(__name__).version
+except DistributionNotFound:
+    __version__ = 'unknown'