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
Merge pull request #552 from jesperronn/update_stacktrace

Update of stacktrace dependency, gives payload optimization