moved hello.sl to tests

tests/hello.expected

@@ -0,0 +1 @@
+hello world

tests/hello.sl

@@ -0,0 +1,6 @@
+import stdlib/stdlib.sl
+import stdlib/io.sl
+
+word main
+    "hello world" puts
+end

tests/hello.test

@@ -0,0 +1 @@
+python main.py tests/hello.sl -o /tmp/hello > /dev/null && /tmp/hello