remove pinned pytz version (#152)

* remove pinned  version

* use a floor of 2018.4 for pytz

* update changelog

Co-authored-by: Collin Simon <csimon@talend.com>

Author: leslievandemark

CHANGELOG.md

@@ -1,4 +1,8 @@
 # Changelog
+
+## 5.12.2
+  * Removes pinned `pytz` version [#152](https://github.com/singer-io/singer-python/pull/152)
+
 ## 5.12.1
   * Removes normalize function from `singer.decimal` to avoid scientific notation [#146](https://github.com/singer-io/singer-python/pull/146)
 

setup.py

@@ -4,13 +4,13 @@
 import subprocess
 
 setup(name="singer-python",
-      version='5.12.1',
+      version='5.12.2',
       description="Singer.io utility library",
       author="Stitch",
       classifiers=['Programming Language :: Python :: 3 :: Only'],
       url="http://singer.io",
       install_requires=[
-          'pytz==2018.4',
+          'pytz>=2018.4',
           'jsonschema==2.6.0',
           'simplejson==3.11.1',
           'python-dateutil>=2.6.0',