issue #56 WIP - Implement Client.post() method everywhere needed

duniterpy/api/bma/blockchain.py

duniterpy/api/bma/network.py

duniterpy/api/bma/tx.py

duniterpy/api/bma/wot.py

examples/create_and_publish_identity.py

examples/save_revoke_document.py

examples/send_certification.py

examples/send_transaction.py