added initial version of Atomic Line List service
added werkzeug dependency (required by atomic package)
install werkzeug on travis run
Python 3 compatibility
more Python 3 compatibility
make imports Python 3 compatible
fix docstring of AtomicLineList.query_object
simplify code
raise an exception if len(wavelength_range) is not 0 or 2
removed outdated comment
got rid of Werkzeug dep again, more Py3 compatibility
fixed map and zip import
atomic: added comments and fixed variable names
atomic: added more comments to explain _parse_result method
atomic: added support for more parameters and adjusted docstring

The following parameters are supported now:

    - wavelength_accuracy

    - element_spectrum

    - minimal_abundance

    - depl_factor

    - nmax

    - multiplet
atomic: added newlines at EOFs
atomic: use the new config system
Merge branch 'master' of github.com:astropy/astroquery into atomic
atomic: added support for the parameters lower and upper level energy range
atomic: added support for `transitions` parameter