fix(gulp): use different transpile options for server and client

for Grunt parity, the server code should be transpiled with with the
`runtime` option

app/templates/gulpfile.babel(gulp).js

@@ -137,7 +137,15 @@ let styles = lazypipe()
     .pipe(plugins.autoprefixer, {browsers: ['last 1 version']})
     .pipe(plugins.sourcemaps.write, '.');<% if(filters.babel || filters.coffee) { %>
 
-let transpile = lazypipe()
+let transpileServer = lazypipe()
+    .pipe(plugins.sourcemaps.init)<% if(filters.babel) { %>
+    .pipe(plugins.babel, {
+        optional: ['runtime']
+    })<% } else { %>
+    .pipe(plugins.coffee, {bare: true})<% } %>
+    .pipe(plugins.sourcemaps.write, '.');
+
+let transpileClient = lazypipe()
     .pipe(plugins.sourcemaps.init)<% if(filters.babel) { %>
     .pipe(plugins.babel, {
         optional: ['es7.classProperties']
@@ -255,13 +263,13 @@ gulp.task('styles', () => {
 
 gulp.task('transpile:client', () => {
     return gulp.src(paths.client.scripts)
-        .pipe(transpile())
+        .pipe(transpileClient())
         .pipe(gulp.dest('.tmp'));
 });<% } %>
 
 gulp.task('transpile:server', () => {
     return gulp.src(_.union(paths.server.scripts, paths.server.json))
-        .pipe(transpile())
+        .pipe(transpileServer())
         .pipe(gulp.dest(`${paths.dist}/${serverPath}`));
 });
 
@@ -335,7 +343,7 @@ gulp.task('watch', () => {
 
     plugins.watch(paths.client.scripts) //['inject:js']
         .pipe(plugins.plumber())<% if(filters.babel || filters.coffee) { %>
-        .pipe(transpile())
+        .pipe(transpileClient())
         .pipe(gulp.dest('.tmp'))<% } %>
         .pipe(plugins.livereload());