Don't include French Guiana in France's coordinates

[joannecheng]

When we select France in the choropleth world map, French Guiana gets included (see the Northeast corner of South America).

I removed the coordinates for French Guiana from the France feature in world.json, created a new feature for French Guiana, ran topojson world.json -o world.topo.json, then ran grunt build. Please let me know if I missed anything or need to do anything else to make this PR merge-able.

[markmarkoh]

This looks great @joannecheng, thanks for fixing this. The only issue with with the topojson command, by default topojson drops all properties but we actually want to carry over a property.

I have to add a 'Contribution' section to the README, but for now the topojson command should look more like:

topojson --id-property iso_a3 -p name=name_long -p name -o world.topo.json world.json

[joannecheng]

@markmarkoh Done! Updated all the files with the output from the fixed topojson command.

[markmarkoh]

Thanks @joannecheng