Bump boto3 from 1.7.63 to 1.7.64 (#297)

Bumps [boto3](https://github.com/boto/boto3) from 1.7.63 to 1.7.64.
- [Release notes](https://github.com/boto/boto3/releases)
- [Changelog](https://github.com/boto/boto3/blob/develop/CHANGELOG.rst)
- [Commits](boto/boto3@1.7.63...1.7.64)

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

Author: dependabot[bot]

requirements.txt

@@ -1,6 +1,6 @@
 asn1crypto==0.24.0
 auth0-python==3.3.0
-boto3==1.7.63
+boto3==1.7.64
 botocore==1.10.64
 cachetools==2.1.0
 certifi==2018.4.16