This worked for me:
exclude: [/bower_components/, /node_modules/]
module.loaders
A array of automatically applied loaders.
Each item can have these properties:
test: A condition that must be met
exclude: A condition that must not be met
include: A condition that must be met
loader: A string of "!" separated loaders
loaders: A array of loaders as string
A condition can be a RegExp, an absolute path start, or an array of one of these combined with "and".
See http://webpack.github.io/docs/configuration.html#module-loaders