Release 1.0.2

Added

• Add LICENSE file (was documented in package.json, but physical file was
  missing)
• Add "description", "bugs", "homepage" keys to package.json
• Add "addBaseLayer" event listener
• Export Leaflet's tileLayer method as addLayer

Changed

• Change default map view from continental United States to African pole of
  inaccessibility
• Adjusted tslint config to detect unused imports and variables
• Adjusted lint script to automatically fix errors when possible
• Change author email address

Removed

• Removed tileLayers export from namespace -- instead, use Object.values()
  on namedTileLayers
• Removed add as default export -- call .add explicitly