v0.4.0 release plan

[abuccts]

Features:

• Cell as SKU in intra-vc scheduler. @abuccts Cell as SKU in intra-vc scheduler #34
  • Spec and algorithm design.
  • Intra-vc implementation.
  • End-to-end tests.
  • Document and test cases.
• Visualizations, including physical cluster, virtual cluster, jobs, etc. @hzhua
  • Visualization prototype.
  • UX design.
  • Webportal implementation.