Edits to the materials needed for windows users

[phillybroadbent]

On windows I had to add encoding="utf-8" to data_f = open('./eva-data.json', 'r', encoding="utf-8") and data_t = open('./eva-data.csv','w', encoding="utf-8") to run the code without an error

python -m pip freeze > requirements.txt needs to be python.exe -m pip freeze > requirements.txt

[anenadic]

There is an issue about encoding: #114. We should really fix this as this is good practice (if you do fix this issue - make sure we propagate the correct code in various branches/rest of the course material).

Not sure about python.exe - just python used to work fine in the past. Perhaps some alias/path setting on your machine @phillybroadbent ?

[smangham]

We discussed this in today's session - it would be great to staple the encoding fix onto the end of the venv section. It's a quick fix but it's a teachable point about platform dependence and implied defaults.