WIP: Removed the deprecated iris.fileformats.grib.

[pelson]

I mostly worked off of e45acf7#diff-319dea6a401e00cbfd00d1aa0969c6a4 to figure out what was still using iris.fileformats.grib.

I've not touched tools/translator and tools/gen_translations.py as I'm not certain how much of that has moved over to iris_grib.

[pelson]

I haven't touched lib/iris/tests/integration/format_interop/test_name_grib.py - we need to do some more work to remove the full integration testing from iris-core.

[pelson]

Some of the docs talk about iris.fileformats.grib.as_pairs - it's not clear to me what the deprecation path was in our previous release wrt. this. Some more detail on the docs will be needed (as a follow-up to this PR).

[pelson]

Lots of tests timing out (as per #2618). One peculiar failure that I'm not able to reproduce locally:

======================================================================
FAIL: test_pep8_conformance (iris.tests.test_coding_standards.TestCodeFormat)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/travis/miniconda/envs/test-environment/lib/python2.7/site-packages/Iris-2.0.0.dev0-py2.7-linux-x86_64.egg/iris/tests/test_coding_standards.py", line 215, in test_pep8_conformance
    '{}'.format('\n  '.join(unexpectedly_good)))
AssertionError: Some exclude patterns were unnecessary as the files they pointed to either passed the PEP8 tests or do not point to a file:
  */src/conf.py
  */src/developers_guide/gitwash_dumper.py
-------------------- >> begin captured stdout << ---------------------
... stopped

[pelson]

FWIW: SciTools/iris-grib#82 ports the iris.fileformats.grib functionality to iris_grib.

[pelson]

Merged in #2810