CHANGELOG.md: Add changes for version 0.5.2

Switch to a personal fork of SolrClient so that we can use kazoo 2.5.0
and get rid of the error about the 'async' keyword on Python 3.7. Also
this bumps some of the other libraries to their latest versions.

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+### [0.5.2] - 2018-10-28
+## Changed
+- Update library versions in requirements.txt
+
 ### [0.5.1] - 2018-10-24
 ## Changed
 - Use Python's native json instead of ujson

requirements.txt

@@ -1,4 +1,4 @@
-certifi==2018.8.24
+certifi==2018.10.15
 chardet==3.0.4
 falcon==1.4.1
 gunicorn==19.9.0
@@ -6,7 +6,7 @@ idna==2.7
 kazoo==2.5.0
 psycopg2-binary==2.7.5
 python-mimeparse==1.6.0
-requests==2.19.1
+requests==2.20.0
 six==1.11.0
-SolrClient==0.2.1
+-e git://github.com/alanorth/SolrClient.git@c629e3475be37c82770b2be61748be7e29882648#egg=SolrClient
-urllib3==1.23
+urllib3==1.24