schema changed; update SQL queries to find distance schools

[techieshark]

• fixes #294 - can now search for distance schools again:

• schema change documentation: https://github.com/CodeforAustralia/school-finder/issues/294#issuecomment-263490977

[Rustuma]

Works - all 12 schools with C (Distance Centre) or S (Distance School) are showing. Merge away

[techieshark]

👍 thanks!