Use PAM as a schedule optimiser

[fredshone]

There is a demonstration of a schedule optimiser in the charypar-nagel branch. Demo notebook here: https://github.com/arup-group/pam/blob/charypar-nagel/notebooks/reschedule.ipynb

There are two (very bad) optimising algos implemented already: https://github.com/arup-group/pam/tree/charypar-nagel/pam/optimise

The ultimate application of this work is to optimise activity times and durations for a given population of 24 hour (MATSim) plans. This process will assume trip durations, locations (and modes) are fixed, so is just concerned with finding the optimum activity times and durations. Scoring will be based on some arbitrary (utility) function - the charypar-nagel util function is already implemented for this work and included in the existing demo.

One of the known use cases for this work is to search for better initial plans before progressing to simulation.

Tasks:

• implement a test case that can be used to a) test quality of optimisation and b) check performance of optimisation (ie how long it takes)
• develop and test new algos
• get code in a state (inc tests) that it can be used on real project