Functional tests (#543)

Functional tests (#543)

* add integration test

* tiny refactor

* add chain tests

* update wallet tests

* add wallet rollback test

* mock utxo, create asset, account

* fix can't find btm asset

* fix verify control program failed

* add tx tests

* tx test, output large than input

* add gas used test

* validate tx when gen block

* add tx version tests

* add gas only tx, spend immature coinbase output tests

* add block header tests

* spent retire, insufficient assets tests

* add coinbase tx test

* golint

* add double spend tests

* tx have no outputs test

* chain fork tests

* GenerateGenesisBlock for tests

* separate unit tests and functional tests

* update status with ProcessBlock

* fix tests

* gofmt

* add tx pool tests

* simplify code

* fix typo

* add max block gas test

* remove useless code

* fix chain tests

* serialize tx manually

* remove mux vm verify

* tmp save

* change the code style

* edit code format

* rename the file

* mv validate block to right folder

* delete unused from validation package

* add unit test for checkBlockTime && checkCoinbaseAmount

* delete unused test_file

* update the blockindex import

* fix tests

* format protocol level

* fix for golint

* edit for fix bug

* fix chain rollback tests