Update contest_leaderboard.sql

Update weather-observation-station.20.sql (#7)

Update placements.sql (#6)

Merge pull request #3 from ShubhiKhanna/patch-1

Merge pull request #4 from ShubhiKhanna/patch-2

Create weather-observation-station-7.sql

Create weather-observation-station-6.sql

Create weather-observation-station-5.sql

Create weather-observation-station-4.sql

Create weather-observation-station-3.sql

Create weather-observation-station-1.sql

Merge pull request #2 from despagito/patch-1

solution using regexp

Remove WIP flag from README

Merge pull request #1 from dhayalramk/master