Bump sqlalchemy from 1.2.6 to 1.2.8 (CloudBotIRC#243)

Bumps [sqlalchemy](https://bitbucket.org/zzzeek/sqlalchemy) from 1.2.6 to 1.2.8.
- [Changelog](https://bitbucket.org/zzzeek/sqlalchemy/src/master/CHANGES)
- [Commits](https://bitbucket.org/zzzeek/sqlalchemy/commits)

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

Author: dependabot[bot]

requirements.txt

@@ -14,7 +14,7 @@ pyenchant==2.0.0
 pythonwhois==2.4.3
 requests==2.19.1
 requests-oauthlib==1.0.0
-SQLAlchemy==1.2.6
+SQLAlchemy==1.2.8
 tweepy==3.6.0
 watchdog==0.8.3
 yarl==1.1.1