diff --git a/.eslintignore b/.eslintignore
index d80776538..e41f53192 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -1,4 +1,7 @@
 /build
 /material
 /site
-/lib
+
+# Temporary
+/tests/regression
+/lib/tasks/tests/regression
diff --git a/.eslintrc b/.eslintrc
index f7cfbd0b0..6f081f879 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -42,7 +42,7 @@
   "rules": {
     "array-callback-return": 2,
     "array-bracket-spacing": 2,
-    "arrow-body-style": 2,
+    "arrow-body-style": [2, "always"],
     "arrow-parens": [2, "as-needed"],
     "arrow-spacing": 2,
     "block-scoped-var": 2,
diff --git a/.travis.yml b/.travis.yml
index 62110e081..cacb79b7c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -39,7 +39,6 @@ addons:
 # Install dependencies
 before_script:
   - sudo pip install -r requirements.txt
-  - npm install
 
 # Perform build and tests
 script: npm run build
diff --git a/Gulpfile.babel.js b/Gulpfile.babel.js
index cd533025c..fb5224e30 100755
--- a/Gulpfile.babel.js
+++ b/Gulpfile.babel.js
@@ -60,8 +60,8 @@ const args = yargs
  * Override gulp.src() for nicer error handling.
  */
 const src = gulp.src
-gulp.src = (...glob) =>
-  src.apply(gulp, glob)
+gulp.src = (...glob) => {
+  return src.apply(gulp, glob)
     .pipe(
       plumber(function(error) {
         util.log(util.colors.red(
@@ -86,12 +86,14 @@ gulp.src = (...glob) =>
         if (args._[0] !== "watch")
           throw error
       }))
+}
 
 /*
  * Helper function to load a task
  */
-const load = task =>
+const load = task => {
   require(`./${config.lib}/tasks/${task}`)(gulp, config, args)
+}
 
 /* ----------------------------------------------------------------------------
  * Images
@@ -114,12 +116,12 @@ gulp.task("assets:images:build:svg",
  */
 gulp.task("assets:images:build", args.clean ? [
   "assets:images:clean"
-] : [], () =>
-  gulp.start([
+] : [], () => {
+  return gulp.start([
     "assets:images:build:ico",
     "assets:images:build:svg"
   ])
-)
+})
 
 /*
  * Clean images generated by build
@@ -152,7 +154,7 @@ gulp.task("assets:javascripts:build", (args.clean ? [
 ] : []).concat(args.lint ? [
   "assets:javascripts:lint"
 ] : []), () => {
-  gulp.start([
+  return gulp.start([
     "assets:javascripts:build:application",
     "assets:javascripts:build:modernizr"
   ])
diff --git a/bin/lint b/bin/lint
index 44371fa95..41cf7902d 100755
--- a/bin/lint
+++ b/bin/lint
@@ -27,5 +27,18 @@ if [ ! -d ../node_modules ]; then
   exit 1
 fi
 
-# Run command
+# Run ESLint
+$(pwd)/node_modules/.bin/eslint .
+ESLINT=$?
+
+# Run Sass-Lint
 $(pwd)/node_modules/.bin/sass-lint -c .sass-lint.yml -vq
+SASSLINT=$?
+
+# If one command failed, exit with error
+if [ $ESLINT == 1 ] || [ $SASSLINT == 1 ]; then
+  exit 1
+fi;
+
+# Otherwise return with success
+exit 0
diff --git a/bin/start b/bin/start
index 539e42e8c..43ac70f6b 100755
--- a/bin/start
+++ b/bin/start
@@ -22,7 +22,6 @@
 
 # Check if "npm install" was executed
 if [ ! -d $(pwd)/node_modules ]; then
-  ls $(pwd)
   echo "\"node_modules\" not found:"
   echo "npm install"
   exit 1
diff --git a/lib/tasks/assets/javascripts/build/application.js b/lib/tasks/assets/javascripts/build/application.js
index 58dfb6e5a..f29e29a88 100644
--- a/lib/tasks/assets/javascripts/build/application.js
+++ b/lib/tasks/assets/javascripts/build/application.js
@@ -40,7 +40,7 @@ export default (gulp, config, args) => {
         stream({
           entry: [
             "whatwg-fetch",
-            "application.js",
+            "application.js"
           ],
           output: {
             filename: "application.js",