TST: Add more tests for rasterio engine

[snowman2]

Continuation of #281

In the process of doing this:

1. I noticed xarray.open_rasterio was being tested instead of rioxarray.open_rasterio, so I updated that.
2. Added fix for missing arguments in the engine.

[codecov]

Codecov Report

Merging #293 (e5e10cf) into master (497c718) will increase coverage by 1.30%.
The diff coverage is 0.00%.

❗ Current head e5e10cf differs from pull request most recent head 06baf6f. Consider uploading reports for the commit 06baf6f to get more accurate results

@@            Coverage Diff             @@
##           master     #293      +/-   ##
==========================================
+ Coverage   92.61%   93.91%   +1.30%     
==========================================
  Files          13       13              
  Lines        1395     1398       +3     
==========================================
+ Hits         1292     1313      +21     
+ Misses        103       85      -18     

Impacted Files	Coverage Δ
rioxarray/xarray_plugin.py	0.00% <0.00%> (ø)
rioxarray/raster_array.py	97.61% <0.00%> (-0.69%)	⬇️
rioxarray/_io.py	92.52% <0.00%> (+6.37%)	⬆️

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