update dask and dask.distributed

[delgadom]

Workflow

• [x] Closes issue #31
• [x] Notebook:worker pairing builds & passes local build, visual inspection & client.map tests
• [x] Passes travis tests
• [x] Image deployed on dev branch (see notebook and worker dev tags)
• [x] Worker passes manual deployment test on compute.rhg
• [x] Notebook+worker passes test-hub deployment
• [x] Updates integrated into downstream images

Summary

Updates dask & dask distributed packages in notebook & worker

• dask-core=0.18.2
• dask-glm=0.1.0
• dask-ml=0.7.0
• dask-searchcv=0.2.0
• dask=0.18.2
• distributed=1.22.1