Add dependences to tasks so that they can be asynchronously carried out by miners

[steffencruz]

Here are the tasks:

1. {'description':'Find libraries', 'acceptance_criteria':'A suitable list of libraries is found wiht well-justified explanations','dependencies':()}
2. {'description':'Write main.py', 'acceptance_criteria':'main.py contains functions a b c which do x,y,z','dependencies':(1)}
3. {'description':'Write test.py', 'acceptance_criteria':'tests all functions in main.py','dependencies':(1,2)}
4. {'description':'Demo app', 'acceptance_criteria':'Run main.py and show that it prints hello world, and that test passes','dependencies':(1,2,3)}
5. {'description':'Design logo', 'acceptance_criteria':'Logo effectively communicates the brand','dependencies':()}

[steffencruz]

https://www.youtube.com/watch?v=yj-wSRJwrrc&t=3s

[steffencruz]