Replace ShareLaTeX with Overleaf in name of multiple project download file (Closes: #963)

services/web/app/coffee/Features/Downloads/ProjectDownloadsController.coffee

@@ -32,7 +32,7 @@ module.exports = ProjectDownloadsController =
 				return next(error) if error?
 				res.setContentDisposition(
 					'attachment',
-					{filename: "ShareLaTeX Projects (#{project_ids.length} items).zip"}
+					{filename: "Overleaf Projects (#{project_ids.length} items).zip"}
 				)
 				res.contentType('application/zip')
 				stream.pipe(res)

services/web/test/unit/coffee/Downloads/ProjectDownloadsControllerTests.coffee

@@ -112,7 +112,7 @@ describe "ProjectDownloadsController", ->
 			@res.setContentDisposition
 				.calledWith(
 					'attachment',
-					{filename: "ShareLaTeX Projects (2 items).zip"})
+					{filename: "Overleaf Projects (2 items).zip"})
 				.should.equal true
 
 		it "should record the action via Metrics", ->