Add some week utils, pass through 'per_page' count.
Add functions for getting start/end of week
Add a 'weekly' view
Use default gravatar when running on localhost
Remove 'Hello'
Move week start/end code to helpers.
Add 'Weeks' to base navigation.
Add 'weeks' to the global ctx instead of per-page.
Put date ranges in weeks menu
Add 'weekly' support to the json api
Clean up 'weekly' param
Add a test for week_start and week_end
Merge branch 'weekly-by-person' of https://github.com/mreid-moz/standup into master