Bump boto3 from 1.12.4 to 1.12.5

Bumps [boto3](https://github.com/boto/boto3) from 1.12.4 to 1.12.5.
- [Release notes](https://github.com/boto/boto3/releases)
- [Changelog](https://github.com/boto/boto3/blob/develop/CHANGELOG.rst)
- [Commits](boto/boto3@1.12.4...1.12.5)

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

requirements.txt

@@ -1,5 +1,5 @@
 asn1crypto==1.3.0
-boto3==1.12.4
+boto3==1.12.5
 bcrypt==3.1.7
 certifi==2019.11.28
 cffi==1.14.0