Print progress output from gulp hygiene

Travis fails the build if it doesn't output anything for a long time

.travis.yml

@@ -46,7 +46,7 @@ install:
   - ./scripts/npm.sh install
 
 script:
-  - node_modules/.bin/gulp hygiene --silent
+  - node_modules/.bin/gulp hygiene
   - node_modules/.bin/gulp electron --silent
   - node_modules/.bin/gulp compile --silent --max_old_space_size=4096
   - node_modules/.bin/gulp optimize-vscode --silent --max_old_space_size=4096

build/gulpfile.hygiene.js

@@ -256,8 +256,16 @@ const hygiene = exports.hygiene = (some, options) => {
 		.pipe(gulpeslint.formatEach('compact'))
 		.pipe(gulpeslint.failAfterError());
 
+	let count = 0;
 	return es.merge(typescript, javascript)
-		.pipe(es.through(null, function () {
+		.pipe(es.through(function (data) {
+			count++;
+			if (count % 10 === 0) {
+				process.stdout.write('.');
+			}
+			this.emit('data', data);
+		}, function () {
+			process.stdout.write('\n');
 			if (errorCount > 0) {
 				this.emit('error', 'Hygiene failed with ' + errorCount + ' errors. Check \'build/gulpfile.hygiene.js\'.');
 			} else {