The Steadiest Team

A quiz league ranks teams by their median round score, so one lucky round can't carry a team.

teams is a dictionary: each key is a team name and each value is that team's list of round scores.

Write best_median_team(teams) that returns the name of the team with the highest median.

• Use statistics.median.
• If two or more teams tie for the highest median, return the one that comes first A to Z.
• There's always at least one team, and every team has at least one score.

(Owls' median is 6. Foxes' median is 3, even though they scored the single best round.)