[Py]Add version to ngraph python (#2193)

* [Py]Add version to ngraph python

* FIX

python/ngraph/__init__.py

@@ -15,6 +15,9 @@
 # ******************************************************************************
 """ngraph module namespace, exposing factory functions for all ops and other classes."""
 
+from pkg_resources import get_distribution
+__version__ = get_distribution('ngraph-core').version
+
 from ngraph.ops import absolute
 from ngraph.ops import absolute as abs
 from ngraph.ops import acos