Bump python-gnupg from 0.3.7 to 0.4.4

Bumps [python-gnupg](https://bitbucket.org/vinay.sajip/python-gnupg) from 0.3.7 to 0.4.4.
- [Commits](https://bitbucket.org/vinay.sajip/python-gnupg/branches/compare/0.4.4..0.3.7)

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

Author: dependabot[bot]

requirements.client.txt

@@ -9,7 +9,7 @@ SQLAlchemy==1.1.11
 Werkzeug==0.12.2
 itsdangerous==0.24
 python-dateutil==2.6.0
-python-gnupg==0.3.7
+python-gnupg==0.4.4
 pytz==2016.10
 WTForms==2.0.2
 Flask-WTF==0.12