Update docs with supported libraries (#266)

* Update index.rst

* version pinning pymysql

Pymysql v1.0.0 only supports python3.6+
https://github.com/PyMySQL/PyMySQL/blob/master/CHANGELOG.md

* Update tox.ini

* fixing pymysql versions

Author: srprash

docs/index.rst

@@ -22,11 +22,16 @@ Currently supported web frameworks and libraries:
 * aioboto3/aiobotocore
 * aiohttp >=2.3
 * boto3/botocore
+* Bottle
 * Django >=1.10
 * Flask
-* httplib
+* httplib/http.client
 * mysql-connector
-* Pynamodb
+* pg8000
+* psycopg2
+* pymongo
+* pymysql
+* pynamodb
 * requests
 * SQLAlchemy
 * sqlite3

tox.ini

@@ -26,7 +26,6 @@ deps =
     django31: Django==3.1.*
     django{22,30,31}: django-fake-model
     pynamodb >= 3.3.1
-    pymysql
     psycopg2
     pg8000
     testing.postgresql
@@ -36,6 +35,10 @@ deps =
 
     # Python2 only deps
     py{27}: enum34
+    
+    # pymysql deps
+    py{27,34,35}: pymysql < 1.0.0
+    py{36,37,38}: pymysql >= 1.0.0
 
     # Python3.5+ only deps
     py{35,36,37,38}: aiohttp >= 3.0.0