Fix *occassional* npm install failures on Travis CI

https://github.com/travis-ci/travis-ci/issues/2244#issuecomment-55473829
mentions creating the npm directory manually as a temporary workaround
Merge pull request #1824 from maurizi/fix-travis-npm

Fix Travis CI npm install issues
No leading or trailing blanks in UDF names

* Data migration to delete existing ones
* `strip` before saving
* Update a test to ensure leading and trailing blanks removed
Merge pull request #1820 from RickMohr/trim-udf-names

No leading or trailing blanks in UDF names
Get valid i-Tree codes by region from ecoservice

Fixes false negatives when an i-Tree code is valid for a region but no OTM code references it.

Requires OpenTreeMap/ecobenefits#43
Merge pull request #1826 from RickMohr/get-itree-codes-from-ecoservice

Get valid i-Tree codes by region from ecoservice
Skip tests requiring i-Tree code validation if ecoservice not running
Merge pull request #1829 from RickMohr/skip-tests-if-no-ecoservice

Skip tests requiring i-Tree code validation if ecoservice not running
Fix merging of i-Tree code field

In the "merge species" UI, for the i-Tree code "imported value", display just region/code pairs which differ from the species, rather than the raw import value (which may have region/code pairs which match the species).

* When storing an i-Tree pair, use `(region, code)` instead of `(code, region)`
* When detecting diffs, use string version of i-Tree code field rather than pair version
* When displaying a diff, for the "imported value" use the value in the diff rather than the value in the row
* Fix `collected_fields` logic in `views._get_row_data`
Merge pull request #1827 from RickMohr/fix-itree-code-merging

Fix merging of i-Tree code field
Add basic species resolver
PR Fixup: Update fields on species match

For presentation reasons
PR Fixup: Don't send empty values up to server
Add typehead to importer species resolver
PR Fixup: gate on genus, not species
PR Fixup: explain pk workaround
PR Fixup: gate species resolver creating on import type