Reset current working directory in all mode

Fix #6

mjtest/cli.py

@@ -96,9 +96,11 @@ if True:#__name__ == '__main__':
         args["mode"] = new_mode
     if args["mode"] == "all":
         report_subdir = datetime.now().strftime("%d-%m-%y_%H-%M-%S")
+        cwd = os.path.realpath(".")
         for mode in [TestMode.lexer, TestMode.syntax, TestMode.ast, TestMode.semantic,
                      TestMode.compile_firm_only, TestMode.compile_only,
                      TestMode.compile_firm, TestMode.compile]:
+            os.chdir(cwd)
             args["all_exec_tests"] = True
             args["report_subdir"] = report_subdir + "_" + mode
             cprint("Run {} tests".format(mode), attrs=["bold"])