Removed pint dependency (#1012)

* Removed pint dependency

* Commented out test_quantity.py

* Removed quantity.py and test_quanity.py

Author: hpohekar

setup.py

@@ -30,7 +30,6 @@
     "appdirs>=1.4.0",
     "pandas>=1.1.5",
     "h5py>=3.7.0",
-    "pint>=0.18",
 ]