Fix wallet unlock when using keyring

Memo
* make prefix changeble
Transationbuilder
* sign() return the signed struct now
Graphenerpc
* Session are used for requests
* Singleton for websocket instance added
* Both measures reduce ram consumption when more than one Steem object is created.
Add missing scrypt package to dependency

secp256k1 is faster than cryptography and put first

Try again with secp256k1

Account
* Improved some function, so that account works limited on GOLOS
Blockchain
* sync changes from python-bitshares
Instance
* sync changes from python-bitshares
Steem
* Improved some functions so that steem works on GOLOS
Chains
* Added GOLOS
graphenebase/Account
* derive256address_with_version added
ecsdasig
* Huge speed improvement (200%) by using cryptography
benchmark added
* benchmark for beemgraphenebase/account funcions
* benchmark for ecdsa
* benchmark for sign/verification of all transaction
Examples
* compare sign/verificaiton speed with steem
Unit tests
* use memo unittests from steem-js
* add key_format unittests from steem-js
* Improved the ecdsa tests

Account
* get_withdraw_routes added
* get_account_votes fixed for appbase
* get_vote, has_voted added
* virtual_op_count, get_curation_reward curation_stats added
* get_account_history and history_reverse added
* history improved
Blockchain
* hash_op added
CLI
* default vote weight added
* upvote added
* Info improved
Steem
* get_block_interval added
Transactionbuilder
* txbuffer.clear() added on exception
Vote
* AccountVotes fixed
GrapheneRPC
* Websocket disconnect exception handling improved
Compare_With_steem_python_account.py added
Unittests for account improved

Transactionbuild
* Automatic Signing with owner key removed
Beembase/account and beembase/bip38 removed as they are using beemgraphenebase/bip38 and beemgraphenebase/account

Amount
* fix json export
Blockchain
* improved get_estimated_block_num
Comment
* Bugfixes
Market
* Use FilledOrder for trades and recenttrades
Price
* FilledOrder fixed
* UpdateCallOrder and PriceFeed removed
Vote
* Bugfix
Unit tests
More unittests for Amount, Blockchain and comment

Bug fix for account
Block structure changed, is alwas {'block': , 'id'} now.
block function removed, Block is used now
Bug fix in comment
Discussions_by_payout removed
Several bugfixes in witness
More exception added to steemnoderpc
Unit tests for appbase nodes with parameterized added
steemnoderpc-unittest added

Wallet contains steem instance

Tox.ini improved

Unit tests fixed for STEEM-style encrypted memos

Account:
* sp vp properties added
* print_info improved
* reputation -> get_reputation
* voting_power -> get_voting_power
* steem_power -> get_steem_power
precision removed
balance -> get_balance

CLI
* set, config createwallet, walletinfo, addkey, listkeys, listaccounts and changewalletpasswordphrase added

create_account_with_delegate added

Unittests
Unit tests fixed and added

Click and prettytable added to requirements
CLI added with following commands:
* balance
* info
Unit tests for CLI added

Python2 comp
* str comp added
* py23 with py23_bytes added with unit tests
* moved back to __bytes__
* super() made compatible with python 2
Account:
* allow and disallow moved from steem
* small improvements
Comment
get_votes added
Steem
* Doku improved
Vote
* bug fixes
* printAsTable
Wallet
* getPostingKeyForAccount added
test_vote added
test_testnet added
test_py23 added

reduced dependency
this allow easier pushing to conda-forge

print_info added
voting_power, steem_power, get_voting_value_SBD, get_recharge_time, get_followers, get_following, get_bandwidth, interest added
The following operations were added:
unfollow, follow, update_account_profile, approvewitness, disapprovewitness, update_memo_key, transfer, transfer_to_vesting, convert,
transfer_to_savings, transfer_from_savings, transfer_from_savings_cancel, claim_reward_balance, delegate_vesting_shares, withdraw_vesting
Comment:
The following operations were added:
upvote, downvote, vote, edit, reply, comment_options, post, resteem
Discussion
all possible discussion_by_... functions were added.
Market
volume24h, orderbook, trades, market_history, accountopenorders fixed or added
buy, sell, cancel fixed
steem
register_api
refresh_data added
get_dynamic_global_properties, get_feed_history, get_reward_fund, get_current_median_history_price, get_next_scheduled_hardfork, get_hardfork_version, get_network,
get_state, get_config  moved from blockchain
steem_per_mvest, vests_to_sp, sp_to_vests, sp_to_sbd, sp_to_rshares, get_median_price, get_payout_from_rshares
custom_json added
utils
make_patch added
witness
feed_publish and update added

Apply fix #42 and #41 from https://github.com/xeroc/python-bitshares