Improve doc

.travis.yml

Makefile

README.rst

beem/account.py

beem/amount.py

beem/blockchain.py

beem/instance.py

beem/memo.py

beem/notify.py

beem/transactionbuilder.py

beem/vote.py

beem/wallet.py

beem/witness.py

beemapi/steemnoderpc.py

beemapi/websocket.py

docs/account.rst

docs/amount.rst

docs/asset.rst

docs/beem.account.rst

docs/beem.aes.rst