Update pip requirement from <=19.2,>=9 to >=9,<19.3

Updates the requirements on [pip](https://github.com/pypa/pip) to permit the latest version.
- [Release notes](https://github.com/pypa/pip/releases)
- [Changelog](https://github.com/pypa/pip/blob/master/NEWS.rst)
- [Commits](https://github.com/pypa/pip/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

setup.py

@@ -11,7 +11,7 @@
     'botocore>=1.12.86,<2.0.0',
     'typing==3.6.4;python_version<"3.7"',
     'six>=1.10.0,<2.0.0',
-    'pip>=9,<=19.2',
+    'pip>=9,<19.3',
     'attrs>=17.4.0,<20.0.0',
     'enum-compat>=0.0.2',
     'jmespath>=0.9.3,<1.0.0',