website: better approach to npm shebang issue

Some tests were still failing b/c the tests themselves used
npm and thus hit the shebang length problem. The new
approach (hopefully) solves this problem by creating a
wrapper npm script that invokes "node path/to/real/npm"
under the hood.

Change-Id: Ib6ac091a069e05e7931243727dd2fa8e3f4ab869
1 file changed