Document changes included in v0.3 and impact of including numpy

Author: rlskoeser

CHANGELOG.md

@@ -1,5 +1,20 @@
 # Change Log
 
+## 0.3
+
+- Updated to use numpy `datetime64` to support a greater range of years beyond the 4-digit years supported by python's builtin ``datetime.date`
+- Renamed formatters to converters for more flexibility / scope
+- Support using different converters for input and output (new `format` and `parse` methods)
+- Improve readme with example usage and disclaimers about current functionality
+- Improve documentation for adding new converters
+- Improve documentation for branching guidelines in contributing
+
+
+
+### numpy impact
+
+Performance differences seem to be negligible, but it does increase payloud size.  The virtualenv for installing version 0.2 was 14MB; when installing the newer version with numpy, the virtualenv is 46MB (the numpy folder in site packages is 31MB on its own).
+
 ## 0.2
 
 - Undate and UndateInterval now include an optional label for named dates or time periods