Bump sqlalchemy from 1.2.17 to 1.2.18 in /{{cookiecutter.app_name}}

Bumps [sqlalchemy](https://github.com/sqlalchemy/sqlalchemy) from 1.2.17 to 1.2.18.
- [Release notes](https://github.com/sqlalchemy/sqlalchemy/releases)
- [Changelog](https://github.com/sqlalchemy/sqlalchemy/blob/master/CHANGES)
- [Commits](https://github.com/sqlalchemy/sqlalchemy/commits)

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

{{cookiecutter.app_name}}/Pipfile

@@ -15,7 +15,7 @@ click = ">=5.0"
 # Database
 Flask-SQLAlchemy = "==2.3.2"
 psycopg2 = "==2.7.7"
-SQLAlchemy = "==1.2.17"
+SQLAlchemy = "==1.2.18"
 
 # Migrations
 Flask-Migrate = "==2.3.1"