I guess you are missing the coinbase immaturity here.
Coinbase transaction can only be spent after 100 blocks.
A single generate will not make the coinbase-transaction appear in listunspent. If you do a generate 101 it will (because you mine 100 blocks on top of your "fee block").
Then you should get something like:
{
"txid": "11cc285148b32fd312260a67193875420931b8511b5f34f2991feb5d94901b8e",
"vout": 0,
"address": "n3y4wCJcY8zzim3CWuKpFi6BPPAf6DzhVm",
"scriptPubKey": "2103559b1d5cd126e03b8ee0887ffc1ffd74d34fae49e2e2e65f7708071b032aabf5ac",
"amount": 25.01920001,
"confirmations": 101,
"spendable": true,
"solvable": true
},
Mining fees works in my regtest mode: http://i.imgur.com/RSLRp4M.png
– Jonas Schnelli – 2016-11-10T12:31:10.290