Bump flask-marshmallow from 0.15.0 to 1.2.1

Bumps [flask-marshmallow](https://github.com/marshmallow-code/flask-marshmallow) from 0.15.0 to 1.2.1.
- [Release notes](https://github.com/marshmallow-code/flask-marshmallow/releases)
- [Changelog](https://github.com/marshmallow-code/flask-marshmallow/blob/dev/CHANGELOG.rst)
- [Commits](marshmallow-code/flask-marshmallow@0.15.0...1.2.1)

---
updated-dependencies:
- dependency-name: flask-marshmallow
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -12,7 +12,7 @@ Flask-BabelEx==0.9.4
 Flask-Cors==4.0.1
 Flask-Login==0.6.3
 Flask-Mail==0.9.1
-flask-marshmallow==0.15.0
+flask-marshmallow==1.2.1
 Flask-Migrate==4.0.4
 Flask-Principal==0.4.0
 Flask-Security-Too==5.3.3