Bug fixes:

* Removed ``siggen.VERSION``. Use ``siggen.__version__`` instead. (#83)
* Remove ujson and six dependencies (#80)
* Remove requests dependency by default. You'll need to install the
  ``cli`` extras which cover installing required dependencies for
  scripts. (#80)

  ::

     pip install 'siggen[cli]'

* bug 1743487: remove ``total_frames`` from socorro
* bug 1737691: skip processing for 0-byte dump files
* bug 1741764: add ``RaiseFailFastException`` to prefix list
* bug 1737691: add new ``MinidumpStackwalkRule``
* bug 1737878: return normalized frames in signature result