[CBR-289] Add some golden tests for ToJSON / FromJSON instance of Mnemonic
[CBR-289] Add some golden tests for ToJSON / FromJSON instance of Mnemonic

input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype