Add some OIDC flow tests.

Enable testing for gregui, add a django config for testing.

frontend/src/themes/index.test.ts

@@ -26,14 +26,14 @@ test('Get theme default when set', async () => {
   process.env.REACT_APP_THEME = 'default'
   // eslint-disable-next-line global-require
   const getTheme = require('./index').default
-  expect(getTheme().palette.primary.main).toEqual('#3293ED')
+  expect(getTheme().palette.primary.main).toEqual('#01579B')
 })
 
 test('Get theme default when unknown', async () => {
   process.env.REACT_APP_THEME = 'unknown'
   // eslint-disable-next-line global-require
   const getTheme = require('./index').default
-  expect(getTheme().palette.primary.main).toEqual('#3293ED')
+  expect(getTheme().palette.primary.main).toEqual('#01579B')
 })
 
 export {}