add these tests

[spencercap]

make sure string arg + enum args both work for:

// initWallet('mnemonic', '');
// initWallet('mnemonic', false);
// initWallet('inkey')

// connectWallet('inkey'); // works
// connectWallet('inkey', ''); // works
// connectWallet('inkey', ''); // should not work...
// connectWallet('defly')
// connectWallet(WALLET_ID.INKEY, {config: { src: '' }});
// connectWallet(WALLET_ID.MNEMONIC, false);
// connectWallet(WALLET_ID.MNEMONIC, '123 456');
// connectWallet(WALLET_ID.MNEMONIC); // works but shouldnt really