diff --git a/.gitignore b/.gitignore
index 7c29c87b..080f19aa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@ vendor
 phpunit.phar
 phpunit.phar.asc
 composer.phar
+composer.lock
diff --git a/.travis.yml b/.travis.yml
index 96a0f19c..89131cc1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,12 +6,9 @@ php:
   - 5.5
   - 5.6
   - 7.0
-  - hhvm
+  - 7.1
 
 sudo: false
 
-before_script:
-  - wget -nc http://getcomposer.org/composer.phar
-  - php composer.phar install
-
-script: phpunit --configuration phpunit.xml.dist
+before_script: composer install
+script: phpunit
diff --git a/composer.json b/composer.json
index 1a5e93b5..4244f133 100644
--- a/composer.json
+++ b/composer.json
@@ -23,5 +23,8 @@
             "Firebase\\JWT\\": "src"
         }
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "dev",
+    "require-dev": {
+        "phpunit/phpunit": " 4.8.35"
+    }
 }
diff --git a/composer.lock b/composer.lock
deleted file mode 100644
index 5518ae41..00000000
--- a/composer.lock
+++ /dev/null
@@ -1,19 +0,0 @@
-{
-    "_readme": [
-        "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
-        "This file is @generated automatically"
-    ],
-    "hash": "60a5df5d283a7ae9000173248eba8909",
-    "packages": [],
-    "packages-dev": [],
-    "aliases": [],
-    "minimum-stability": "dev",
-    "stability-flags": [],
-    "prefer-stable": false,
-    "prefer-lowest": false,
-    "platform": {
-        "php": ">=5.2.0"
-    },
-    "platform-dev": []
-}