Edit package.json license to match SPDX id
Edit package.json license to match SPDX id

See [NPM package.json spec for licenses](https://docs.npmjs.com/files/package.json#license) and [SPDX license IDs](https://spdx.org/licenses/)

X-ref: apache/cordova-plugin-device#48

 This closes #24

apache/cordova-plugin-whitelist,apache/cordova-plugin-whitelist,starquake/cordova-plugin-whitelist,starquake/cordova-plugin-whitelist