io_bae.py: Explicitly Set GPF/IPF Column data types on read (#72)

* Add pyproj to list of run requirements in meta.yaml

* io_bae.py: explicitly set data types in GPF/IPF cols on read

* Typo fix

* Add tests for GPF/IPF data types, and making sure GPF/IPF point IDs are written correctly

* typo fix in test_io_bae.py that was breaking tests

* file name typo fix

* correct variable and change file names test_io_bae.py

* correct test_write_str_id_ipf, insert required newline in example IPF file

* Change GPF/IPF int and float lengths to 32 bits

* Increase size of GPF lat/lon/ht to float64

* Change GPF/IPF float lengths back to 64 bits to be consistent with BAE spec

* typo fix

* test_io_bae.py: Specify correct dtypes when reading expecting IPF/GPFs with read_csv

* Add python version to appveyor.yml