This seems to fix the sporadic failure (at least on my machine).

When changing variable names for code review critique, accidental cut/paste prevented intended behavior.

Fix a few remaining tz naive dates

need to import os

Jonahstanley/add navigation tests

Anton/videoalpha tests

Fix for broken forums due to forum entry with no start_date

Switch to using environment variables to get key for Segment.io

Bug fix for LaTeX source not saving

CHANGELOG entry for the whitelistable sandboxing change.

need to comment out another thumbnail check due to build test environmen...

need to comment out another thumbnail check due to build test environment not having libjpeg installed

These CHANGELOGS were never used, and are now obsolete.

css_click will try clicking multiple times.

disable assertions on thumbnail generation as it puts a system requireme...

disable assertions on thumbnail generation as it puts a system requirement on libjpeg which may not be installed on the test machines

and code reorganization

Feature/cale/xblock init