Add POP tx1 grid.

[dabail10]

I have added support for the tx1 POP tripole grid. There is also a test added to base_suite here. Currently it uses the uniform climatological forcing and ice_ic = 'default'. It is mainly for testing purposes. I will add the tripole grid and kmt files to the ftp downloads.

• Developer(s): D. Bailey

• Please suggest code Pull Request reviewers in the column at right.

• Are the code changes bit for bit, different at roundoff level, or more substantial? BFB

• Please include the link to test results or paste the summary block from the bottom of the testing output below.

• Does this PR create or have dependencies on Icepack or any other models? N

• Is the documentation being updated with this PR? (Y/N) Y
  If not, does the documentation need to be updated separately at a later time? (Y/N)

Note: "Documentation" includes information on the wiki and .rst files in doc/source/,
which are used to create the online technical docs at https://readthedocs.org/projects/cice-consortium-cice/.

• Other Relevant Details:

[dabail10]

The checks are failing because the tx1 grid files need to be loaded onto the Travis server.

[apcraig]

Travis seems to be failing due to changes to the ftp input file names. We need to get this resolved. I don't think the tx1 files are needed on the travis server as the travis_suite does not test it.