Remove some training modules

[MaybeJustJames]

• Plotting (depending on outcome of survey)
• Modules (instead talk about importing standard library modules)
• Sets
• complex
• Remove tuple if there's time left

[tmuylder]

• [] Plotting (depending on outcome of survey)
• [x] Modules (instead talk about importing standard library modules)
• [x] Sets
• [] complex
• [] Remove tuple if there's time left

[tmuylder]

Changes in branch remove-stuff-issue15

• [ ] Plotting (depending on outcome of survey)
• [x] Modules (instead talk about importing standard library modules)
• [x] Sets
• [x] complex
• [ ] Remove tuple if there's time left

[tmuylder]

Merged Modules, Sets, Complex stuff. Not plotting and didn't remove tuples

[tmuylder]

Plotting is still part of the course (now three days) Tuples will also remain present for now (as we have three days)