Warnings in RN 0.61

[mifi]

componentWillReceiveProps and componentWillMount are being used by this package, but they are now deprecated by react and their use discouraged. This causes warnings in newest react native. Needs to be rewritten. See:
https://reactjs.org/docs/react-component.html#unsafe_componentwillmount
https://reactjs.org/docs/react-component.html#unsafe_componentwillreceiveprops

[DenisSokoloff]

[surya-moven]

This should take care of them: #192