chore(npm): clean up shrinkwrap file, remove unused properties

from our experiements it appears that the presense or absense of the from and resolved properties
makes no difference on the behavior of  but  updates these properties
with different values depending on different state of the cache and node_modules.

So in order to get clean diffs during updates, we are just going to drop these properties and have
a script to do this automatically.

Long term this should be fixed in npm: https://github.com/npm/npm/issues/3581
chore(clean-shrinkwrap): add a utility to clean up the shrinkwrap file

This is to deal with https://github.com/npm/npm/issues/3581

See the previous commit for more info.

Closes #6672
chore(package.json): update karma to 0.12.0