Make Optimizely per-page opt-in. Bug 1107952.

- Update docs to reflect Waffle configuration.
Switch to the new Docker-based Travis CI builds.
[fix bug 1110848] Remove 'Web We Want' promo from whatsnew/firstrun pages
Merge pull request #2588 from alexgibson/bug-1110848-remove-webwewant-promo

[fix bug 1110848] Remove 'Web We Want' promo from whatsnew/firstrun pages
Update legal-dos to latest master.

Changes:

78996df Merge pull request #268 from GeoffPiperMZ/patch-9
d5e8809 Update en-US.md
8442c99 Clarifications
d99a09f Clarify conversation URLs & direct calls
c6ec83e Change to branding term
ad8cfa2 Clarifications to ToS
a87d1aa Clarifications
7e3dc14 more clarifications in response to governance thread
95ae568 Clarifications in response to governance thread
Fix Bug 1103396 - Move Thunderbird start page to bedrock and make it localizable
Merge pull request #2585 from jpetto/bug-1107952-optimizely-opt-in

Make Optimizely per-page opt-in. Bug 1107952.
Merge pull request #2594 from pmclanahan/try-travis-docker

Switch to the new Docker-based Travis CI builds.
Merge pull request #2600 from pmclanahan/update-legal-docs

Update legal-dos to latest master.
[fix bug 1113136] Stop redirecting Firefox DNT page to Mozilla Taiwan website
Merge pull request #2539 from kyoshino/bug-1103396-thunderbird-start

Fix Bug 1103396 - Move Thunderbird start page to bedrock and make it localizable
[fix bug 1114609] Update UiTour JS lib and documentation for Firefox Hello
Merge pull request #2606 from alexgibson/update-uitour-js-lib

[bug 1114609] Update UiTour JS lib and documentation for Firefox Hello
Bug 1103396: activate thunderbird start page for all locales on dev-allzom.org
Merge pull request #2601 from alexgibson/bug-1113136-stop-redirecting-dnt-mozilla-taiwan

[fix bug 1113136] Stop redirecting Firefox DNT page to Mozilla Taiwan
Merge pull request #2607 from pascalchevrel/thunderbird_start_page

Bug 1103396: activate thunderbird start page for all locales on dev-allizom.org
Enable admin: fix bug 1044184

Add admin staticfiles

Add rna dependencies and ConditionalAuthMiddleware

Add/update rna, django-pagedown

Add ConditionalAuthMiddleware, rna url

Add django-filter and settings.REST_FRAMEWORK

Add collectstatic to update_assets

Remove ctx param from base_update_assets

Clear *.pyc during deploy and move collectstatic

Add rna and api-token-auth PT
Merge pull request #2264 from mozilla/enable-admin

Enable admin: fix bug 1044184