Update dependencies

* Update dev dependencies

* Update dependencies

* Rebuild lockfile

Author: novemberborn

lib/load-config.js

@@ -2,7 +2,7 @@
 const fs = require('fs');
 const path = require('path');
 const vm = require('vm');
-const isPlainObject = require('is-plain-object');
+const {isPlainObject} = require('is-plain-object');
 const pkgConf = require('pkg-conf');
 
 const NO_SUCH_FILE = Symbol('no ava.config.js file');