fix(sdk): Load usbboot adapter on start

Change-type: patch
Changelog-entry: Load usbboot adapter on start on GNU/Linux if running as root.
Signed-off-by: Alexis Svinartchouk <alexis@resin.io>

lib/shared/permissions.js

@@ -70,6 +70,26 @@ exports.isElevated = () => {
   return Bluebird.resolve(process.geteuid() === UNIX_SUPERUSER_USER_ID)
 }
 
+/**
+ * @summary Check if the current process is running with elevated permissions
+ * @function
+ * @public
+ *
+ * @description
+ *
+ * @returns {Boolean}
+ *
+ * @example
+ * permissions.isElevatedUnixSync()
+ *   if (isElevated) {
+ *     console.log('This process has elevated permissions');
+ *   }
+ * });
+ */
+exports.isElevatedUnixSync = () => {
+  return (process.geteuid() === UNIX_SUPERUSER_USER_ID)
+}
+
 /**
  * @summary Get environment command prefix
  * @function