update build and test reqs

Author: karosc

swmm-toolkit/test-requirements.txt

@@ -2,5 +2,5 @@
 
 
 pytest==6.1.1
-numpy==1.19.5
+numpy==1.21.5
 aenum==2.2.6

swmm-toolkit/tools/build-wheels.sh

@@ -52,7 +52,7 @@ done
 
 
 # Install packages and test
-for PYBIN in /opt/python/cp{36,37,38,39,310}*/bin; do
+for PYBIN in /opt/python/cp{37,38,39,310}*/bin; do
     # Setup python virtual environment for test
     ${PYBIN}/python -m venv --clear ./test-env
     source ./test-env/bin/activate