Stwcs

------------------

- Add ``stdout`` to logging handlers. [108]

- Correct the logic for replacing headerlets with one which has a different
distortion model. [109]

------------------

- Correct a problem where best WCS solutions were not applied
with repeated reruns of ``updatewcs``. [95]

------------------

- Improve Travis test matrices to include testing with public and dev
versions of dependencies. [87]

- Fixed a bug in converting a ``PC`` to a ``CD`` matrix. [77]

- Filter out expected warnings from tests. [78]

- Allow ``updatewcs`` to be called with ``HDUList`` objects as input. [80]

- Update the XML parser for the astrometry database and switch the default to use
the MAST TEST server which is publicly accessible. [74]

- Gracefully ignore when the astrometry database returns an empty result for
an image. [84]

- Insure updatewcs works with WFPC2 data while supporting HDUList inputs. [85]

-----------------

- Fix a problem with the build script. [64]

-----------------
- Fix a bug in restoring headerlets from a HeaderletHDU to a SCI extension [60]

- Fix logic to gracefully handle lack of any WCS solutions from the
astrometry database for an exposure. [62]

-----------------

- Fix a bug in creating headerlets from a I/O stream. [39]

- Added an interface to a new astrometry database which will
contain new astrometrically-accurate solutions for the pointing
for HST observations. [40]