Check OS before installing cudatoolkit

Author: seanlaw

conda.sh

@@ -3,7 +3,7 @@
 conda update -y conda
 conda update -y --all
 conda env update --file environment.yml
-if [ `which nvcc | wc -l` -lt "1" ]; then
+if [[ `uname` == "Linux" && `which nvcc | wc -l` -lt "1" ]]; then
     conda install -y -c conda-forge cudatoolkit-dev
 fi
 #conda install -y -c conda-forge numpy scipy numba pandas flake8 flake8-docstrings black pytest-cov