Fixed handling of duplicated form inputs
Do not add forms inputs without name to payload
Updated documentation for Eso package.
Minor sphinx improvement.
Added help option to Eso.instrument_query()
Improved Eso.query_instrument() interface.

Using `columns` and `column_filters` keywords instead of the generic
`**kwargs`.
Improved help for query_instrument()

A checkbox looking like `[ ]` now shows which columns can be
controlled. The default columns in the output are ticked like `[x]`.
Added beautifulsoup4 dependency.
Added beautifulsoup4 to .travis.yml
Small docstring update to instrument_query()
Updated eso package documentation
Merge pull request #314 from jwoillez/form_fix

Some fixes to the way forms are handled in the Eso package
ESO tests: adding more
the ESO "local" test should fail: _activate_form *must* connect to the
internet since it doesn't cache.  We will need monkeypatching to get
tests set up
minor comment
ESO testing: add amber_form, monkeypatchign
(+ a little whitespace)
minor rearrangement in testing
one ESO test completed!
fix py3 problem