Update of stacktrace dependency, gives payload optimization

the recent version excludes /test directory which contained a giant jar file. This reduces size of bower-libs/stacktrace folder
from 7MB to ~150KB

See https://github.com/stacktracejs/stacktrace.js/pull/84

This also references #544 since we have less payload to build and deploy (although I could not notice a speed reference on this particular update)