quilt3 breakage

[sjsrey]

After following our installation instructions, we are getting breakage:

~/Dropbox/t/tobler/github/tobler/tobler/data.py in <module>
      1 from urllib.parse import unquote, urlparse
      2 
----> 3 import quilt3
      4 
      5 

~/anaconda3/envs/tobler/lib/python3.7/site-packages/quilt3-3.1.5-py3.7.egg/quilt3/__init__.py in <module>
      5 warnings.filterwarnings("ignore", message="numpy.dtype size changed")
      6 
----> 7 from .api import (
      8     copy,
      9     put,

~/anaconda3/envs/tobler/lib/python3.7/site-packages/quilt3-3.1.5-py3.7.egg/quilt3/api.py in <module>
      2 from urllib.parse import quote, urlparse, unquote
      3 
----> 4 from .data_transfer import copy_file, get_bytes, delete_url, put_bytes, list_url
      5 from .formats import FormatRegistry
      6 from .search_util import search_api

~/anaconda3/envs/tobler/lib/python3.7/site-packages/quilt3-3.1.5-py3.7.egg/quilt3/data_transfer.py in <module>
     20 from tqdm import tqdm
     21 
---> 22 from .session import create_botocore_session
     23 from .util import QuiltException, make_s3_url, parse_file_url, parse_s3_url
     24 from . import xattr

~/anaconda3/envs/tobler/lib/python3.7/site-packages/quilt3-3.1.5-py3.7.egg/quilt3/session.py in <module>
     20 AUTH_PATH = BASE_PATH / 'auth.json'
     21 CREDENTIALS_PATH = BASE_PATH / 'credentials.json'
---> 22 VERSION = pkg_resources.require('quilt3')[0].version
     23 
     24 def _load_auth():

~/anaconda3/envs/tobler/lib/python3.7/site-packages/pkg_resources/__init__.py in require(self, *requirements)
    898         included, even if they were already activated in this working set.
    899         """
--> 900         needed = self.resolve(parse_requirements(requirements))
    901 
    902         for dist in needed:

~/anaconda3/envs/tobler/lib/python3.7/site-packages/pkg_resources/__init__.py in resolve(self, requirements, env, installer, replace_conflicting, extras)
    789                 # Oops, the "best" so far conflicts with a dependency
    790                 dependent_req = required_by[req]
--> 791                 raise VersionConflict(dist, req).with_context(dependent_req)
    792 
    793             # push the new requirements onto the stack

ContextualVersionConflict: (python-dateutil 2.8.1 (/home/serge/anaconda3/envs/tobler/lib/python3.7/site-packages), Requirement.parse('python-dateutil<=2.8.0'), {'quilt3'})