Readme for last release adapted

Blockchain
* raw_ops added to stream, when set to True stream() produces the same output as the old Blockchain.ops()
Unit tests
* Add unit tests for testing raw_ops

Account
* Parameter accuracy renamed to stop_diff
* Doku for estimate_virtual_op_num improved
* Several improvements and fixes for estimate_virtual_op_num
CLI
* rewards command improved and more paramter added
Comments
* Assure Amount class for all amounts
* is_pending improved
Doku
* tutorial about showing all posts of an account added
Unit tests
* test_account, test_cli and test_comment improved

Account
* print_info improved (Last Vote added)
* entryId changed to start_entry_id in get_feed, get_blog_entries and get_blog
*rpc.get_account_history moved to _get_account_history
* estimate_account_op added, can be used to fastly get account op numbers from dates or block nums
* history and history_reverse uses estimate_account_op
Exception
* KeyNotFound removed
Memo
* raises MissingKeyError instead of KeyNotFound
Price
* small improvement
Steem
* __repr__ added
Transactionbuilder
* get_potential_signatures, get_transaction_hex and get_required_signatures added
* raises MissingKeyError instead of KeyNotFound
VotesObject
* __contains__, __str__ and __repr__ added
Wallet
* raises MissingKeyError instead of KeyNotFound
Witness
* __contains__, __str__ and __repr__ added to WitnessObject
Steemnoderpc
* small improvements
Operationsid
* producer_reward added
Unit tests
* new function added and tests adapted to changes

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