Upgrade `requests` module to 2.3.0
Upgrade `requests-oauthlib` to 0.4.1
Upgrade `oauthlib` to 0.6.3
Add argument.
Add scope/field selector settings for LinkedIn provider.

This change adds three new configuration variables to third_party_auth's LinkedIn provider:

* SOCIAL_AUTH_LINKEDIN_OAUTH2_SCOPE,
* SOCIAL_AUTH_LINKEDIN_OAUTH2_FIELD_SELECTORS,
* SOCIAL_AUTH_LINKEDIN_OAUTH2_EXTRA_DATA

Being able to configure these additional settings is useful if you want
the LinkedIn provider to pre-populate the email field when a new user
registers via the linkedin provider.

The Google provider prepoulates the email field by default, but if you
want LinkedIn to do the same, these two settings should be set to:

SOCIAL_AUTH_LINKEDIN_OAUTH2_SCOPE = ['r_basicprofile', 'r_emailaddress']
SOCIAL_AUTH_LINKEDIN_OAUTH2_FIELD_SELECTORS = ['email-address']

For more info see:
http://psa.matiasaguirre.net/docs/backends/linkedin.html
log stop_video event
The LMS should serve favicon.ico also when a theme is enabled.
Ensure all split methods consuming Keys check that key is fully specified
STUD-1654
Annotation Tools: Removed background-color from image annotations

- Also fixed edit bug when annotation is not created first
- Also fixed indentation issues
XBlocks can disable navigation chrome.

There is an option to:
* Enable/disable accordion navigation
* Enable/disable/repoint tab navigation

This allows for full-screen XBlocks (e.g. a code IDE, or large video
player). It is also the first pass at allowing top-level XBlocks. It's
also now possible to make a chromeless XBlock, point a tab to it, and
make it point back to that tab.

Next steps down that path would be:
* Fix up how tabs are handled. The current version is a hack.
* Create appropriate XBlocks for courseware, tabbed navigation,
  etc. to reach feature parity
* Invert/rejigger the XML format.
Useless code path in import_from_xml causing errors removed
Youtube Video Quality Button Tests
Removed suppress_top_level_nav, as per Cale
Explicit disable_accordion
Review from Cale
Review from Cale
stop update_assets commands from being called extra times
Add Studio handling for changes to group configurations

STUD-1658
Introduce constants for studio_view, student_view, and author_view.
Complete Studio support for handling group configuration changes

STUD-1658