Test the voting with new update contract

[greenhat]

After switching to the new update contract (see ergoplatform/eips#89 ) during #125 #126 we need to vote again to test the process without reward token parameters.

Plan:

Stage 1 (local):

• bootstrap new private pool;
• invite the second oracle;
• test updating epoch_length;
• decrease min_votes to 1; Discovered Refresh NFT error in pool box after updating min_votes  #301
• update epoch length with 1 vote;
• increase min_votes to 2;
• update epoch length with 2 votes (the ballot that skipped the previous vote should work);

Stage 2 (public testnet ERG/XAU pool)

• test voting and update epoch_length;