Problem: BigchainDB election approve returns wrong message

[shahbazn]

Steps to Reproduce:

1. Start a network for 4 nodes
2. Start election process to add another node
3. Once that transaction is committed bring two of the nodes down and run the command below

bigchaindb election approve <election transaction id> --private-key .tendermint/config/priv_validator.json

4. It will stay stuck for a bit and then post the following error

ERROR:bigchaindb.commands.bigchaindb:Failed to commit vote

The error above is not accurate as the transaction is still in the mempool and waiting for enough nodes to be available to be commited.