Get rid of `limit_to` parameter

[rerb]

Replace with something like:

def limit_query_to(query, limit):
    if "limit" in query.lower():
        return query
    else:
        return add_limit(query, limit)

def add_limit(query, limit):
    if query[-1] != ';':
        sub_query = query
    else:
        sub_query = query[0, -1]
    return "{sub_query} LIMIT {limit};".format(
        sub_query=sub_query, limit=limit)

#36 has background on why this change should be made.