added preview button to opportunities page
on preview button click it will redirect you to the preview of the opportunity
added controller file and linked path inside index.html
switching to preview with $stateParams
retrieving opportunity from server
retrieving correct opportunity info from the server
added company property need to retrieve the photo
preview info populated
removed unneccessary code
added button to exit preview mode
preview page fully populated and can be updated
Merge branch 'previewPage' into dev