Latest binary does not run on macos

After #352, new binaries have been released (see the Draft v0.3.0 in the releases page), but error on launch.

<img width="421" alt="screenshot 2019-02-04 at 16 51 40" src="https://user-images.githubusercontent.com/1293565/52219627-50146080-289d-11e9-982a-13ee80234079.png">

Another way to repro: `yarn package` in the root folder, and open `packages/fether-electron/dist/mac/Parity Fether.app`