Have a way to upload geojson data through dgraphloader

[pawanrawal]

Dgraphloader should have a way by which we can upload files with geojson data similar to https://github.com/dgraph-io/dgraphgoclient did earlier.

[pawanrawal]

dgraphloader now supports taking in the list of geo files to load along with the name of the predicate to use for storing the coordinates.

dgraphloader --geo states.rdf.gz,countries.rdf.gz

It can take in a file with a FeatureCollection and it will create an edge for each Feature.

<uid> <loc> "Geometry" .

The predicate has a default value of loc, it can be modified using geopred flag to the loader.