[Changelog] python-steem 0.2.3

Release 0.2.3

New:

• added tests for HF 14.2
• merge steemtools operations with steemlib
• [API] Allow for a list of API nodes #9

Fixes:

• [memo] make memos compliant with steemit.com (close #11)
• [base] more tests
• [base] cleanup from merge
• [exchange] just don't sign if no keys present and don't through an error
• [api] make sure there is a transaction in a block
• fixed the struct ordering for Transfer_from_savings
• [exchange] fix api changes and remove redundancy
• [base] return pub keys on verify signed transactions
• [transactions] Fix proper return of OperationKlass