Bug Report: Library dependencies in unit tests out of date

### Describe the bug

When running the provided unit tests for this repo receiving error:
"ImportError: cannot import name 'Markup' from 'jinja2'"
After further investigaton, discovered that Jinja2>=2.10.1 deprecated Markup command

### To Reproduce
Steps to reproduce the behavior:
1. Submit a pull request with a commit
2. Code runs on unit tests
3. See error

### Screenshots

### Desktop (please complete the following information):
- OS: IOS
- Browser: Chrome
- Version: 22

### Additional context

potentially use this instead to fix:
>>> from jinja2.utils import markupsafe
>>> markupsafe.Markup()
Markup('')

OR have to change dependency versions, when done locally all unit tests ran as usual