1282 reactdaypicker updates date ranges when only start date is selected

[nichhk]

Fixes #1282

• Significantly simplify the way that we pick date ranges in ReactDayPicker. By default, a date range (past week) is already selected. When a date range is already selected and the user clicks on a new date, we don't perform any logic to attempt to preserve the start or end date; we just create an entirely new date range, starting from the date that the user clicked on.
• Update index.js to only retrieve new data when the end date has changed (not start date).

This also fixes a couple bugs around pulling data for new date ranges, in index.js.

• When getting the non-overlapping ranges for two ranges A and B, we need to check whether A and B overlap. This will make a difference in the non-overlapping range.

• When we are resolving the date ranges, if we find that the next date range doesn't overlap with our current one, we need to add the current one to our list of date ranges and then set the new current date range to be the next one.

  • Up to date with dev branch
  • Branch name follows guidelines
  • All PR Status checks are successful
  • Peer reviewed and approved

Any questions? See the getting started guide

[ardada2468]

lgtm but In contact form do we need to console.log state?

[funbunch]

From what I can tell, looks good!