Move node_modules out of lib/ directory

The require() logic in Node is a little hard to understand, as a lot of
documentation on the Internet talks about a require.paths variable
that's now been removed. Pity, because it would have been the perfect
solution for the problem we've been hitting with Astrolabe, where doing
require('astrolabe') fails to find the module. Another solution, setting
the environment variable NODE_PATH=./lib before running Protractor, is
also failing for hard-to-understand reasons. One thing does work,
though, and that's having node_modules in the directory from which the
Node session is launched. In our case, that's the "test" folder.

If we figure out how to do this better in the future, we can move
node_modules back into "test/lib". For now, though, this is the simplest
change to make that gets the job done.