Add a test case for gh-263 box.cfg true/false vlaues

test/app/boolean.test.lua

+#!/usr/bin/env tarantool
+
+--
+-- Check that Tarantool creates configuration accepts boolean values
+-- 
+box.cfg{logger_nonblock=true,
+    panic_on_wal_error=true,
+    logger="tarantool.log"
+}
+print(box.cfg.logger_nonblock)
+print(box.cfg.panic_on_wal_error)
+os.exit()