minor improvements

[Stonelinks]

hey there,

just some small changes i found necessary when using this. thanks for the plugin!

[plwai]

I found that the error information in flipper is converted into another form of object which is not informative. I suggest to have one more field for the error message.

Suggested change

	} catch (error) {
	state.action = { type: action.type };
	state.before = { error };
	state.after = { error };
	currentConnection.send('actionDispatched', state);
	}
	} catch (error) {
	state.action = { type: action.type };
	state.before = { error, message: error.toString() };
	state.after = { error, message: error.toString() };
	currentConnection.send('actionDispatched', state);
	}