Make more obvious the testing and simple(?). Idea is to CI it later.

tools/test.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+import sys
+import ctypes
+
+if __name__ == '__main__':
+
+    if len(sys.argv) < 2:
+        print("Usage: test.py <JContainers DLL filepath>")
+        sys.exit(1)
+
+    argv = ('', '--gtest_filter=*.*')
+
+    errno = -1
+    try:
+        lib = ctypes.cdll.LoadLibrary(sys.argv[1])
+        cargs = (ctypes.c_char_p * len(argv))()
+        for i in range(len(argv)):
+            cargs[i] = argv[i].encode('utf-8')
+        errno = lib.JC_runTests(len(argv), ctypes.byref(cargs))
+    except BaseException as e:
+        print("Error:", e)
+    except:
+        print("Unexpected error:", sys.exc_info()[0])
+    sys.exit (errno)
+