IProvider Example in the README doesn't compile

[markis]

Expected Behavior

Copy and Paste the code in the 'Injecting a Provider (asynchronous Factory)' section of the readme should compile and run.

Current Behavior

error TS2339: Property '_katana' does not exist on type 'Ninja'.
error TS2339: Property '_shuriken' does not exist on type 'Ninja'.

Possible Solution

Update the code to something that compiles

Steps to Reproduce (for bugs)

1.) Copy the code in the 'Injecting a Provider (asynchronous Factory)' section
2.) Paste the code into another file
3.) Run tsc
4.) Error in console

Context

Just trying to learn.

Your Environment

Node.js 5.10

Stack trace

README.md

[markis]

Hi, I like what you all are doing with this project. Just trying to help out when I find things that need addressed.

[remojansen]

Thanks a lot for the PR. Your help is more than welcome we really need people like you to help us to spot issue before we do a production-ready release.