Add json file support

[assafshp]

Allow config method to support json file path to include environment variables

[coveralls]

Coverage remained the same at 100.0% when pulling 91d4b57 on assafshp:master into 825c1b2 on motdotla:master.

[maxbeatty]

Thanks but I think we'd like to stick to our single INI file format. It's easy to emulate dotenv with a few lines of code if you would like to use JSON:

const myEnvConfig = require('.env.json')
for (const key in myEnvConfig) {
  process.env[key] = process.env[key] || myEnvConfig[key]
}

[trainerbill]

@maxbeatty not sure if this is still up for discussion or not, but I would like this functionality as well. I am using Yeoman and it would be nice to be able to use readJSON and change the dotenv configuration in subgenerators. I also use node -r dotenv/config when starting the application.

Your code does work but then I have to carry around an envConfig.js file in all my packages/projects. With the widespread use of dotenv it would be nice to support this. Otherwise I can just publish a module to do the exact same thing with JSON.

Let me know. Thanks!

[maxbeatty]

I'm still in the camp of publishing lots of small, single-purpose modules as opposed to offering more and more configuration of an existing module. I published dotenv-json to get most of the way there. Feel free to contribute or fork.