updated prepublish to use common.npm

The local test case creates a very particular set of executions options, particularly the environment. So, what might our pattern be to "deal" with test cases in the same file that construct different execution options?

* Create a common set of options, EXEC_OPTS, to copy/inherit from locally
```
var execOpts = JSON.parse(JSON.stringify(EXEC_OPTS))
```
* Create a local copy as shown above

I think (1) would be more appropriate and more closely follow the pattern I have already set forth.