First pass of writing a yml to define an import template

- Tree of Sex Plant datasets
Refining template spec

swapped taxonomy columns/keys
Added trait groups
Skeleton of a class to read the template YMLs
Working around in command-line validator to harness new template
Added some functional methods to import_template
Minor tweaks to TreeOfSex.yml template

Removed drop collumns
metadata_columns are now key/value pairs instead of an array
Major rewrite of validator to use an import_template
chr_headers was renamed

import_job will need more work than this
Remove converter.rb
Comments in TreeOfSex.yml template
Update validator - traits are not required
More involved parsing in command line tester
Added csv_import_template resource

Resource supports file uploads, and stores a YAML file that will be
used for the import process
Implemented CRUD interface and inserted into admin menu
Replaced select_trait_headers step with select_template
Refactoring in import_template
Validator now returns trait_headers as hashes with name, groups, format, and values
Rename lib/treeofsex_import to lib/traitdb_import
Working (but incomplete) refactoring of import_job to use templates

Does not recognize trait groups, metadata (notes/comments), or dynamic
taxonomy fields
Add TraitGroup model

has_and_belongs_to_many ContinuousTrait and CategoricalTrait
Add template name to template model