ENH: Add functions to summarize a single template

Previously we could only summarize two templates i. e. requiring that
the user passed a sample and a prep template. This code has been
reworked to only require a template-like object.

Fixes #415
ENH/BUG: Correctly display unique/repeated values

Fixes #541
STY: Add suggestions from @antgonza
STY: Move study_id to the top of the handler
BUG: Fix incorrect investigation type for studies

All the studies that we are currently processing are amplicon sequencing
and thus not defined in the ontology given by EBI, see link below. Since
we knew this, the objects and underlying code submit as "Other" and with
a value for "new_study_type". However the GUI only allowed you to select
from one of the choices that EBI provides.

The problem is explained in more detail in #522 and once that PR is
merged it should be fixed, this change makes it so that the submissions
include correct information.

https://www.ebi.ac.uk/ega/sites/ebi.ac.uk.ega/files/documents/Study.xml
STY: 😱📲
STY: flake-it-up 📲
Merge pull request #545 from ElDeveloper/ebi-minor-fix

BUG: Fix incorrect investigation type for studies
ENH: Only instantiate one study object

We were instantiating several of them and this will reduce some extra
overhead.
Merge pull request #543 from ElDeveloper/issue-415

Show only a sample or a prep metadata summary
Merge branch 'master' of https://github.com/biocore/qiita into add-transaction-blocks
formatting documentation