remove -spec from test files

Author: aminya

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 dist
+spec/tree-view-spec.js*

babel.config.js

@@ -0,0 +1,14 @@
+const presets = [['@babel/preset-env', { targets: { electron: 5 } }]]
+
+const plugins = []
+
+if (process.env.BABEL_ENV === 'development') {
+  plugins.push('@babel/plugin-transform-modules-commonjs')
+}
+
+module.exports = {
+  presets,
+  plugins,
+  exclude: 'node_modules/**',
+  sourceMaps: 'inline',
+}