Bump requests from 2.18.4 to 2.19.1 (CloudBotIRC#247)

Bumps [requests](https://github.com/requests/requests) from 2.18.4 to 2.19.1.
- [Release notes](https://github.com/requests/requests/releases)
- [Changelog](https://github.com/requests/requests/blob/master/HISTORY.rst)
- [Commits](psf/requests@v2.18.4...v2.19.1)

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

Author: dependabot[bot]

requirements.txt

@@ -12,7 +12,7 @@ nltk==3.2.5
 psutil==5.4.5
 pyenchant==2.0.0
 pythonwhois==2.4.3
-requests==2.18.4
+requests==2.19.1
 requests-oauthlib==0.8.0
 SQLAlchemy==1.2.6
 tweepy==3.6.0