Updated API creds

[developersteve]

Updated with env system vars instead of coded ones, also updated readme

[realJoshByrnes]

@developersteve I'm happy to support these changes, but there's information missing from README.md about setting/requiring system environment variables.

I'm also having a hard time deciding on on supporting backwards-compatibility, which won't require much effort at the moment, but may do so in the future.

What are your thoughts? ~JD

[developersteve]

@ozjd Was using it for some samples and found it easier to set export vars rather than hard code so thought id push the changes. In hindsight with the new api coming it may not be needed anyway.

Up to you if you want to update

Ah yeah you are right i can update the other parts of the readme if you wanted to add it in

[realJoshByrnes]

@developersteve If you could update the README, I'll merge the pull request, and I'll make any changes for backwards compatibility shortly.