Remove TS 2.1 syntax from .d.ts files for backwards compatibility with TS 1.8
npm install dts-downlevel
This utility modifies .d.ts files generated using TS 2.1.
It removes any new syntax that is incompatible with TS 1.8.
This allows a library to be develped using TS 2.1, but consumed by an app that uses TS 1.8.
npm i --save-dev dts-downlevel
Command line use:
```
dts-downlevel [paths]
If [paths] is omitted, all .d.ts files in the current directory and below are modified.
#### Example
dts-downlevel 'dist//.d.ts' 'build//.d.ts'`
To see the rules that this utility currently supports, view the source code: https://github.com/christopherthielen/dts-downlevel/blob/master/rules.js