Initial commit of 03_no_migration_isolated_mating.py simulation

1. Mainly covers the initial commit of 03_no_migration_isolated_mating.py.

2. Included an empty class dose_functions inside dose.py to serve as an empty class of custom functions which is to be inherited by the simulation file's simulation_function.

3. Updated genetic.py that fixes a bug that makes all instances of Organism class reference to the same status dictionary for every individual's status dictionary. (See obsolete solution: 75766b7e27d73be10affb6e57790cc1bea367f42)