need to create a new queue for frontend modules that must be returned right away

[kevinkle]

this is a problem as modules like the database status views also use rq multiples which wont return anytime soon if there are long-running analyses also occurring

issue overlaps with #115

the new workers will likely become:

1. priority > multiples > backlog
2. priority > singles
3. blazegraph
4. priority

[kevinkle]

I'm adding the priority queue to backlog and singles, but also creating a separate container with some workers solely handling priority (similar to the way blazegraph queue is setup)

[kevinkle]

Getting and error:

modules.beautify.beautify.beautify({'disable_amr': False, 'i': '/datastore/2017-06-30-21-53-27-595283-GCA_000023365.1_ASM2336v1_genomic.fna', 'disable_vf': False, 'disable_serotype': False, 'pi': 90, 'options': {'pi': 90, 'amr': False, 'serotype': True, 'vf': True}}, '/datastore/2017-06-30-21-53-27-595283-GCA_000023365.1_ASM2336v1_genomic.fna_rgi.tsv_rgi.p') from multiples
b50e9cb9-8f34-43dd-82c8-f43282147c67
Failed 3 days ago
Traceback (most recent call last):
  File "/opt/conda/envs/backend/lib/python2.7/site-packages/rq/worker.py", line 700, in perform_job
    rv = job.perform()
  File "/opt/conda/envs/backend/lib/python2.7/site-packages/rq/job.py", line 500, in perform
    self._result = self.func(*self.args, **self.kwargs)
  File "./modules/beautify/beautify.py", line 124, in beautify
    json_r = check_alleles(json_r)
  File "./modules/beautify/find_widest.py", line 126, in check_alleles
    raise Exception('The Panadas DF from gene_dict is empty.')
Exception: The Panadas DF from gene_dict is empty.

The same error happened in the past when rgi wasnt run before beautifying. However, it looks like the pickle dump /datastore/2017-06-30-21-53-27-595283-GCA_000023365.1_ASM2336v1_genomic.fna_rgi.tsv_rgi.p isnt empty.

[kevinkle]

Added in #137