Simplify creating a new provider from boilerplate

[AaronFriel]

Creating a new provider from the boilerplate requires a good deal of manual find-and-replace. Either #86 or another method should be considered to make it easier to start a repository from scratch, e.g., to not assume the GitHub org is "pulumi" or the NPM scope is "@pulumi".

[iwahbe]

Issues that would have been fixed:

• Cannot build tfgen for Pulumi provider for Dynatrace  #113

[danielrbradley]

This has been completed in #135 which introduces a new setup.sh script which does more of the heavy lifting with the replacements.

This will likely be improved further as we extend the integration testing via #137