Port the main page to boostrap.css
Port the main page to boostrap.css

Nothing has to be done as the page is mostly empty.

Change-Id: I2471f7d0faf492a4924f295652c4dd0f0fbea8de

Linaro/lava-server,Linaro/lava-server,Linaro/lava-server,Linaro/lava-server