tavern test missing API calls for full coverage

all available hivemind API calls covered

missing API call tests:

• hive.db_head_state
• hive.get_info
• tags_api.get_active_votes - result is randomly ordered, maybe we should change it to be deterministic?

deprecated API calls:

• condenser_api.get_account_votes
• tags_api.get_account_votes

not implemented API calls:

• follow_api.get_blog_authors
• follow_api.get_feed
• follow_api.get_feed_entries
• tags_api.get_tags_used_by_author
• tags_api.get_discussions_by_active
• tags_api.get_discussions_by_cashout
• tags_api.get_discussions_by_votes
• get_discussions_by_children

it would be good to decide if we should remove or implement this functions.