pins jinja2 version < 3

[janash]

This PR pins the version of jinja2 installed in the environment. The package pandas_profiling uses 'escape' from 'jinja2.utils', which is not present in jinja2 version 3. The environment file as in the original repo results in installation of the latest jinja version.

Tested on Windows 11 and Ubuntu 20.04 (through WSL).

Without pinning, jinja2 version 3.1.2 is installed. With pinning, jinja2 version 2.11.3 is installed.

Output from 0b-check_dependencies.ipynb without pin:

[ OK ] pandas version 1.0.5
[FAIL] Error in importing pandas_profiling: cannot import name 'escape' from 'jinja2.utils' (/home/janash/miniconda3/envs/bestpractices/lib/python3.7/site-packages/jinja2/utils.py)
[ OK ] matplotlib version 3.2.2
[ OK ] seaborn version 0.10.1
[ OK ] sklearn version 0.22.2.post1
[ OK ] scipy version 1.4.1
[ OK ] tqdm version 4.43.0
[ OK ] jupyter_client version 7.4.9
[ OK ] ipywidgets version 8.0.4
[ OK ] torch version 1.3.1

After pinning jinja2:

[ OK ] pandas version 1.0.5
[ OK ] pandas_profiling version 2.8.0
[ OK ] matplotlib version 3.2.2
[ OK ] seaborn version 0.10.1
[ OK ] sklearn version 0.22.2.post1
[ OK ] scipy version 1.4.1
[ OK ] tqdm version 4.43.0
[ OK ] jupyter_client version 7.4.9
[ OK ] ipywidgets version 8.0.4
[ OK ] torch version 1.3.1