Add school district overlay layer
Add school district overlay layer

* Use the school district layer added in #735 as an overlay
layer.

kdeloach/model-my-watershed,WikiWatershed/model-my-watershed,project-icp/bee-pollinator-app,lliss/model-my-watershed,project-icp/bee-pollinator-app,kdeloach/model-my-watershed,project-icp/bee-pollinator-app,WikiWatershed/model-my-watershed,lliss/model-my-watershed,kdeloach/model-my-watershed,kdeloach/model-my-watershed,WikiWatershed/model-my-watershed,project-icp/bee-pollinator-app,lliss/model-my-watershed,WikiWatershed/model-my-watershed,kdeloach/model-my-watershed,WikiWatershed/model-my-watershed,lliss/model-my-watershed,lliss/model-my-watershed