Add MIT license to package.json

[perbernhardt]

The "license" property in the package.json is not correctly set. Thereby the library is regarded as "unlicensed" by tools like e.g. Snyk.

I created a PR to solve this: #71

Any chance to get this merged rather quick, @tolbertam?

[perbernhardt]

@daniellohausenleanix FYI

[perbernhardt]

@mikejihbe or @larzconwell do you have write access to this repository?

[larzconwell]

@perbernhardt Sorry but I do not have write access and certainly do not have the ability to publish the changes in #71.

From recent history it looks like the only person who has published changes has been @tolbertam but even that was 3 years ago, I unfortunately do not know the current status of this project but I think it's fair to say that it's not being actively maintained.