chore(spec-tests): add missing newlines

NODE-1295

Author: mbroadst

test/tests/spec/connection-string/valid-host_identifiers.json

@@ -151,4 +151,4 @@
       "options": null
     }
   ]
-}
+}

test/tests/spec/connection-string/valid-warnings.json

@@ -65,4 +65,4 @@
       }
     }
   ]
-}
+}