Know how: add a new tree and worker to the Timetable

New tree&set of workers can be added to the Synergy Scheduler in next steps:

1. Define a Worker in the context.py. Let us call it PROCESS_ALPHA

   process_context = {
   ...
   PROCESS_ALPHA: _process_context_entry(
       process_name=PROCESS_ALPHA,
       classname='workers.process_alpha_module.ProcessAlphaModule.start',
       token=TOKEN_ALPHA,
       time_qualifier=QUALIFIER_DAILY,
       state_machine_name=STATE_MACHINE_CONTINUOUS,
       blocking_type=BLOCKING_NORMAL,
       trigger_frequency='every 60',
       present_on_boxes=['dev.*']),
   ...
   }

2. Define constants in constants.py:

   PROCESS_ALPHA = 'ProcessAlpha'
   TOKEN_ALPHA = 'alpha'
   TREE_ALPHA = 'tree_alpha'

3. Declare a governing tree. Let us call it TREE_ALPHA and assume that it will enclose PROCESS_ALPHA only.
   Should TREE_ALPHA has any dependencies on other trees, list them by tree name in dependent_on field:

   timetable_context = {
   ...
   TREE_ALPHA: _timetable_context_entry(
       tree_name=TREE_ALPHA,
       enclosed_processes=[PROCESS_ALPHA],
       dependent_on=[],
       mx_name=TOKEN_APHA,
       mx_page=MX_PAGE_TRAFFIC)
   ...
   }

4. Start the Scheduler, as advised in Go to