Unit tests fixed

Formatting of all doc parts improved
Logo and icon added
Doc structure improved
quickstart improved

Account:
* add appbase calls
* Parse all amounts
Asset
* Made appbase ready
* supports different asses, diffined in chains.py
Block
* add appbase calls
blockchain
* improve get_estimated_block_num
* add threaded blocks method
Comments
* add appbase calls
Discussions
* add appbase calls
Market
* add appbase calls
Steem
* current_median_history_price -> get_current_median_history
* get_reward_fund -> get_reward_funds
* get_next_scheduled_hardfork -> get_hardfork_properties
* get_hardfork_version removed
* get_reserve_ratio added
* get_witness_schedule added
Transactionbuilder
* appbase calls added
Vote
* appbase calls added
Wallet
* appbase calls added
Witness
*appbase calls added
* WitnessesByIds removed
* LookupWitnesses -> ListWitnesses
steemnoderpc
* Uses now GrapheneRPC
* appbase property added
* get_use_appbase added
* network_version added in check
Chains
* chain for appbase added
* assets restructured
* min_version added
Graphenapi removed
Graphenesrpc removed
graphenerpc added
* supports websocket and http, authomatic switching depending on the https or wss.
* Checks the blockchain_version, if 0.19.4 -> appbase ready
* Add appbase logig
* Handing for request and websocket added
Examples
* benchmark_beem is ready for appbase
* print_appbase_calls added
* print_comments added
* watching the watchers added
Unit tests fixed

reduced dependency
this allow easier pushing to conda-forge