package.json:
"peerDependencies": {
"typescript": "*"
}
This way it uses the TypeScript version that you want and you are not stuck with 1.4.1.
I'm not the only one to want this, I'm using this repository: https://github.com/SierraSoftworks/typescript-require instead of the official one.
See commits SierraSoftworks@09cb95b and SierraSoftworks@1beba3d