Give the development user dashboard permissions
Add a footer

Adding a footer helps the user figure out when the page has ended.

Also it means that forms don't go right up until the end of the page,
making it harder to submit.
Add module creation to dashboard form
Remove unused variables.
Use MultiDict for wtforms

Use MultiDict class for input to wtforms form so that modules can be
loaded.
Fix dashboard tests and pep8

parse_modules_from_session no longer exists
Allow get_module_choices to fail in development

This is required for the tests to run in travis.
Upgrade performanceplatform-client

The new endpoints in the admin API are now supported in the admin client
(AdminAPI). Make use of these in the admin app to get the benefit of
things like backoff and gzipping, and simplify the admin app code
slightly.

Controversially, this introduces a TESTING environment variable that is
set during testing, and used in production code. This is because the
admin app needs to speak to the admin API at startup to get the
available module types for the form select field.