npm module improvement and tests

Flag option passed to `.installPackage()` in "lib/npm.js" may be
an array of options to pass to `npm install`

All Tests in "test/test.npm.js" have been completed.

Test utilities have been improved
Fix Tests

Tests errored due to incorrect writing of JSON into file by
`.writeJSON` in "test/utils.js". All things well now.

Removal of a `console.log` invocation in "test/utils.js"