add travis generated documentation page

• a bit more cleanup

initial package draft release

TaskDriver broadcasts / distributes a function / task (fn; e.g. loop_task1) over indices (indx; e.g. file indices). Aside from indx, other parameters can be read from a file called task.yml within e.g. loop_task1.

So far this has been tested manually for four included tasks:

• vectorized interpolation (loop_task1)
• satellite Chl derivation (loop_task2)
• export rate derivation (loop_task3)
• daily climatology averaging (loop_task4)