Add the ability to repeat the previous weeks deliveries

[rmeritz]

The feature was originally described in this issue: https://github.com/bocoup/blocks-capacity-planner/issues/5

Description:

• Added a new button "Copy Previous Schedule" that allows users to copy from the previous week's schedule.
• Copy from the previous week to time range described by the current scheduling constraint.
• Use bulk creates API because otherwise, copy takes too many operations per second.
• Only allow copy if
  1. There is no current assignment to avoid overwriting or deleting data that shouldn't be overwritten or deleted.
  2. And the time period is a week or less because the behavior if the time period is larger, is ill-defined, unlikely to be used, and needs a bunch of complexity to be implemented
• Disable the button copy button if it cannot be used and display a tooltip describing why.

Additional Thoughts about UI/Edge cases:

• I had originally wanted to use the Tooltip to describe what the feature did but couldn't easily display a bunch of info in a Tooltip. I think the feature is pretty self-explanatory so this isn't really needed. But I could go back and add a ConfirmationDialouge to provide more context about what is going to happen and allow a user to confirm.
• I was worried about what would happen if the producer or consumer is removed between the weeks when you copy, but with the bulk API no errors are thrown and these assignments just don't get created. Seeing as it is an edge case the restaurant/hospital is removed but the delivery is left on the table is an edge case I think this is fine, but maybe it would be better to alert the user.
• I was also worried about what if the capacity changes for a hospital week to week so that there are too many deliveries after the copy. This is another unlikely edge case that I was planning on alerting the users too, but I see the UI already shows a warning if the Hospital is overcapacity so I think its fine to just use the existing UI as again it is an unlikely edge case. I could add additional checks to the UI but it becomes hard to maintain. I looked into reusing the existing checks is the onAssign function but that doesn't work with the need to do the operation in bulk.

Other Cleanup Done:

• Cleanup of eslint config. Added mocha to the environment and added a plugin for mocha style guides.
• Added instructions for how to use a debugger for testing. I tried but couldn't figure out how to get mocha to pass the --debug argument to node directly so I could just add a command to package.config.
• Merged in the indentation PR and fixed indentation in existing tests

[jugglinmike]

@rmeritz While experimenting with the code, I found it was creating a bunch of extra assignments in the table. They weren't visible from the Block because they were all being created for dates that preceded the interval I had selected, but I could see them in the Grid view.

The problem came from the fact that we created a "moment" instance outside of an iteration and called its subtract method inside an iteration. Unfortunately (and I mean that: state is awful) moment#subtract mutates the underlying object. For every assignment we considered, we extended the "start date" 7 days farther into the past.

The tricky part is that this only matters when you are filtering more than one assignment. So even though you wrote a test for the "ignore early dates" condition, it included just one assignment--not enough to trigger the bug.

I moved the "start date" calculation outside of the forEach predicate so that it's consistent across every iteration, and I extended the test to "prove" the correction.

Does that look right to you?

[rmeritz]

I moved the "start date" calculation outside of the forEach predicate so that it's consistent across every iteration, and I extended the test to "prove" the correction.

Does that look right to you?

Thanks for the through QA is looks good to me.