Merge pull request #186 from darabun/master

(feat) Dashboard Styling. Color theme change
Merge pull request #187 from darabun/master

(refactor) Remove dummy links.
(feat) Serve device data for campaigns
(cleanup) Clean the schema.sql
(inc) Adds ab_click_device table and initiate it whenever ab_test created
(inc) working on initializing ab_click_device
(feat) Modify db schema/ serve device/click data to front-end
Merge pull request #196 from darabun/master

(feat) Style campaign page
Merge pull request #199 from nrobeR/feat/device

Feat/device
(feat) Change drag and drop styling