Community - Fix Reputation API Definitions

[economicstudio]

While I was debugging other reputation problem (steemit/steem#3241), I found that there are several errors in the current definition.

• accounts:string array => account_lower_bound:string
• curl -s --data '{"jsonrpc":"2.0", "method":"reputation_api.get_account_reputations", "params": {"account_lower_bound": "steem"}, "id":1} https://api.steemit.com` doesn't work! It should be curl -s --data '{"jsonrpc":"2.0", "method":"reputation_api.get_account_reputations", "params": {"account_lower_bound": "steem", "limit":1}, "id":1}' https://api.steemit.com
• other minor errors and update.

I'll submit PR.