Case `06_account_name_conflict` does not behave according to specifcation

[jakub-zarembinski]

from pyteos.eosf import *
reset() 
create_wallet()
create_master_account("master")
create_account("alice", master)
create_account("carrol", master)
create_account("alice", master)

>>> reset()
Removing testnet cache for prefix `_127_0_0_1_8888_`
Testnet cache successfully removed.
Local node is stopped [].
...
Local node is running. Block number is 6
>>> create_wallet()
* Wallet name is ``_127_0_0_1_8888_default``, wallet directory is
    /home/sygnet/eosio-wallet/.
* Created wallet ``_127_0_0_1_8888_default``.
* Password is saved to the file ``_127_0_0_1_8888_passwords.json`` in the wallet directory.
* The wallet is empty.
>>> create_master_account("master")
######### Create a master account object ``master``.
* Importing keys of the account ``eosio`` into the wallet ``_127_0_0_1_8888_default``
* Cross-checked: all account keys are in the wallet.
* Account object ``master`` stored in the file
    ``_127_0_0_1_8888_accounts.json`` in the wallet directory:
    /home/sygnet/eosio-wallet/_127_0_0_1_8888_accounts.json
>>>
>>> create_account("alice", master)
######### Create an account object ``alice``.
... for a new blockchain account ``3sgw12dumuqd``.
* The account object is created.
* Cross-checked: account object ``alice`` mapped to an existing account ``3sgw12dumuqd``.
* Importing keys of the account ``3sgw12dumuqd`` into the wallet ``_127_0_0_1_8888_default``
* Cross-checked: all account keys are in the wallet.
* Account object ``alice`` stored in the file
    ``_127_0_0_1_8888_accounts.json`` in the wallet directory:
    /home/sygnet/eosio-wallet/_127_0_0_1_8888_accounts.json
>>> create_account("carrol", master)
######### Create an account object ``carrol``.
... for a new blockchain account ``osdym3re2fcc``.
* The account object is created.
* Cross-checked: account object ``carrol`` mapped to an existing account ``osdym3re2fcc``.
* Importing keys of the account ``osdym3re2fcc`` into the wallet ``_127_0_0_1_8888_default``
* Cross-checked: all account keys are in the wallet.
* Account object ``carrol`` stored in the file
    ``_127_0_0_1_8888_accounts.json`` in the wallet directory:
    /home/sygnet/eosio-wallet/_127_0_0_1_8888_accounts.json
>>> create_account("alice", master)
######## Account object ``alice`` restored from the blockchain.