Incorporating fixes to V4 material
This PR turns a simple `+` into a `+=` so that end dates for bootcamps are actually incremented by one day - according to the standard, end dates are non-inclusive, so two-day events are showing up as one-day events.
Merge pull request #508 from gvwilson/extending-calendar-dates

Fixing end dates for bootcamps
Reminder about today's lab meeting
Adding Spelman and reminding people about the lab meeting
Merge branch 'master' of github.com:swcarpentry/site