new DOI badge, citation file
require C++ compiler in travis
add jinja2 req to travis (for astropy dev)
update built-in des bandpasses
update DES bandpass metadata
Merge pull request #49 from kbarbary/new-des-bandpasses

update built-in des bandpasses
BUGFIX: SNANA VARNAMES / VARLIST (read_snana_ascii)
Merge pull request #51 from dannygoldstein/snana-fix

BUGFIX: SNANA VARNAMES / VARLIST (read_snana_ascii)