Cleanup build process (#1140)

* Cleanup build process

avoiding bash subshells (which happen in for loops) because they
like to selectively inherit environment variables

* address restrictions of osx sip

see https://github.com/nteract/nteract/issues/1523#issuecomment-284027093
diff --git a/Makefile b/Makefile
index 933e46e..837148c 100644
--- a/Makefile
+++ b/Makefile
@@ -443,11 +443,9 @@
 TESTS += test_mips.static test_ppc.static test_sparc.static
 TESTS += test_systemz.static test_x86.static test_xcore.static
 TESTS += test_skipdata test_skipdata.static test_iter.static
-check:
-	@for t in $(TESTS); do \
-		echo Check $$t ... ; \
-		LD_LIBRARY_PATH=./tests ./tests/$$t > /dev/null && echo OK || echo FAILED; \
-	done
+check: $(TESTS)
+test_%:
+	./tests/$@ > /dev/null && echo OK || echo FAILED
 
 $(OBJDIR)/%.o: %.c
 	@mkdir -p $(@D)