Migrate Jade to Pug template engine

Jade templates engine has been renamed to Pug.

We are using Pug already on the Blender Cloud repository, following is Flamenco and Attract

src/templates/users/edit_embed.pug

@@ -89,7 +89,7 @@ script(type="text/javascript").
 		//- console.log($(this).serialize());
 		$.post($(this).attr('action'), $(this).serialize())
 		.done(function(data){
-			// This function is defined in index.jade.
+			// This function is defined in index.pug.
 			displayUser('{{ user._id }}')
 			.done(function() {
 				$('#user-edit-notification').addClass('success').html('Success!');

src/templates/users/index.pug

@@ -103,7 +103,7 @@ script(src="{{ url_for('static_pillar', filename='assets/js/vendor/jquery.select
 
 script(type="text/javascript").
 
-	// This function is also used in edit_embed.jade.
+	// This function is also used in edit_embed.pug.
 	function displayUser(userId) {
 		var url = '/u/' + userId + '/edit';
 		return $.get(url, function(dataHtml){