Bump boto3 from 1.7.4 to 1.7.6

Bumps [boto3](https://github.com/boto/boto3) from 1.7.4 to 1.7.6.
- [Release notes](https://github.com/boto/boto3/releases)
- [Changelog](https://github.com/boto/boto3/blob/develop/CHANGELOG.rst)
- [Commits](https://github.com/boto/boto3/compare/1.7.4...1.7.6)

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

requirements.txt

@@ -17,7 +17,7 @@ requests==2.18.4
 datadog==0.8.0
 networkx==1.11
 pathlib2==2.3.0
-boto3==1.7.4
+boto3==1.7.6
 
 # Needed for the mongo_* modules (playbooks/library/mongo_*)
 pymongo==3.2.2

requirements3.txt

 # Needed for SES limits check job
-boto3==1.7.4
+boto3==1.7.6
 awscli==1.15.4