Bump gunicorn from 19.9.0 to 19.10.0 (#101)

Bumps [gunicorn](https://github.com/benoitc/gunicorn) from 19.9.0 to 19.10.0.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@19.9.0...19.10.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

requirements.txt

@@ -1,7 +1,7 @@
 beautifulsoup4==4.8.0
 elasticsearch==5.5.3
 flask-cors==3.0.8
-gunicorn==19.9.0
+gunicorn==19.10.0
 nested-lookup==0.2.18
 pylint==2.3.1
 python-memcached==1.59