Bump psycopg2 from 2.7.7 to 2.8 in /{{cookiecutter.app_name}}

Bumps [psycopg2](https://github.com/psycopg/psycopg2) from 2.7.7 to 2.8.
- [Release notes](https://github.com/psycopg/psycopg2/releases)
- [Changelog](https://github.com/psycopg/psycopg2/blob/master/NEWS)
- [Commits](https://github.com/psycopg/psycopg2/commits)

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

{{cookiecutter.app_name}}/Pipfile

@@ -14,7 +14,7 @@ click = ">=5.0"
 
 # Database
 Flask-SQLAlchemy = "==2.3.2"
-psycopg2 = "==2.7.7"
+psycopg2 = "==2.8"
 SQLAlchemy = "==1.3.2"
 
 # Migrations