Added SPARSEZOO_TEST_MODE flag for makefile (#174)

Author: kevinaer

Makefile

@@ -6,6 +6,7 @@ CHECKGLOBS := 'examples/**/*.py' 'integrations/**/*.py' 'scripts/**/*.py' 'src/*
 DOCDIR := docs
 MDCHECKGLOBS := 'docs/**/*.md' 'docs/**/*.rst' 'examples/**/*.md' 'integrations/**/*.md' 'notebooks/**/*.md' 'scripts/**/*.md'
 MDCHECKFILES := CODE_OF_CONDUCT.md CONTRIBUTING.md DEVELOPING.md README.md
+SPARSEZOO_TEST_MODE := "true"
 
 BUILD_ARGS :=  # set nightly to build nightly release
 TARGETS := ""  # targets for running pytests: keras,onnx,pytorch,pytorch_models,pytorch_datasets,tensorflow_v1,tensorflow_v1_models,tensorflow_v1_datasets