MacOS M1-compatibility issues

Docker images wouldn't build and run on my Mac with an M1 chip as configured.

* adding `--platform linux/amd64` to the `docker build` and `docker run` commands resolves this issue.
* Also port 5000 appears to be in use by [Apple's AirPlay receiver](https://developer.apple.com/forums/thread/682332) but it works with a different host port, e.g. `-p 5050:5000`

```Makefile
image:
docker build --platform linux/amd64 -t snowflake_data_profiler .

container:
docker run --platform linux/amd64 -it -p 5050:5000 snowflake_data_profiler
```

Also, there were a series of ImportErrors due to changes in Flask/gunicorn dependencies that required pinning certain libraries at specific versions prior to features in use being removed from the upstream libraries.

```requirements.txt
markupsafe==2.0.1
itsdangerous==2.0.1
werkzeug==2.0.3
```