Convert Program.js to async/await

Author: alexcanessa

lib/src/Program.js

@@ -27,20 +27,18 @@ class Program {
      *
      * @return {Promise}
      */
-    init() {
-        return this._getEnvOptions()
-            .then(options => {
-                this.options = this._filterObject(this._camelCaseObjectKeys(
-                    Object.assign(
-                        {},
-                        this.defaults,
-                        Object.assign({}, ...[].concat(options)),
-                        this.options
-                    )
-                ));
-
-                return this.options;
-            });
+    async init() {
+        const options = await this._getEnvOptions();
+        this.options = this._filterObject(this._camelCaseObjectKeys(
+            Object.assign(
+                {},
+                this.defaults,
+                Object.assign({}, ...[].concat(options)),
+                this.options
+            )
+        ));
+
+        return this.options;
     }
 
     /**