Ticks for NCL_lcnative_1.py and similar examples

[kafitzgerald]

Due to some limitations in Cartopy, we don't currently have ticks on the plot in example NCL_lcnative_1.py (and likely other examples). This is noted in the the comments of the example itself, but wasn't logged as an issue.

Logging this here so it's easier to track and since it came up again in a request from the GeoCAT suggestion box.

There's also a related issue over on GeoCAT-viz to clarify whether or not the ticks functionality there supports Cartopy GeoAxes: NCAR/geocat-viz#332

Additionally, there's a relevant Stack Overflow thread here: https://stackoverflow.com/questions/27962953/cartopy-axis-label-workaround