Generalise regular interpolation.
Re-instate testing of coding standards.
Update licence headers.
Add FieldCollation -> metadata conversion.

Adds iris.experimental.fieldsfile.convert_collation().
Add data attribute
Adjust PYTHONPATH for building PyKE rules.

And tart the rest up a bit.
Review changes
Rename _data attribute
Merge pull request #1398 from rhattersley/coding-standards

Re-instate testing of coding standards.
Fixed a typo in `guess_coord_axis` docstring.
Merge pull request #1405 from ocefpaf/fix_typo

Fixed a typo in `guess_coord_axis` docstring.
Improve data tests
Merge pull request #1400 from rhattersley/collation-to-cube

Add FieldCollation -> metadata conversion.
Merge pull request #1402 from dkillick/add_ff_data

Add data attribute to FieldCollation
Extended the env variables for Iris's travis-ci testing.
Review changes.
Fix cube.copy() for scalar cubes.
Merge pull request #1381 from rhattersley/generalise-interp

Generalise regular interpolation.
Ran the system tests with default tests on travis.ci.
Fix vector dims shape for scalar value