Setup versioning (aws#134)

NihalHarish · rahul003 · commit a7988efcc3a2 · 2019-08-21T11:05:02.000-07:00
* added _verion.py and support

* fixed __init__.py

* using PEP 440 standard versioning it.
diff --git a/tornasole/_version.py b/tornasole/_version.py
@@ -1 +1 @@
-__version__ = "0.4"
+__version__ = "0.4a"
