Uncaught error:

Hit an uncaught error with the gdal.open() method earlier today:

/Users/mapsam/mapbox/node-wmtiff/node_modules/gdal/lib/gdal.js:546
			return driver.create.apply(driver, args);
			                     ^

Error: Error creating dataset
    at Error (native)
    at Object.open (/Users/mapsam/mapbox/node-wmtiff/node_modules/gdal/lib/gdal.js:546:25)
    at Object.reproject (/Users/mapsam/mapbox/node-wmtiff/index.js:59:22)
    at Object.<anonymous> (/Users/mapsam/mapbox/node-wmtiff/bin/wmtiff:17:8)
    at Module._compile (module.js:409:26)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at Function.Module.runMain (module.js:441:10)
    at startup (node.js:139:18)

Let's add a try/catch around this so we can return something more useful.

cc @GretaCB

Start in index.js at the reproject call on line 59, then inspect bin/wmtiff where the result is consumed. Reproduce the gdal.open() failure and determine how the command currently handles it; done means the failure returns a more useful error instead of remaining uncaught.