Revert system test changes:

* Revert "Shutdown rippled before http server in json rpc test to avoid http server potentially receiving messages due to automatic ledger close interval."
* Revert "Update ripple-lib integration tests"

This reverts commit 83442825e5.

package.json

@@ -10,7 +10,7 @@
   },
 
   "dependencies": {
-    "ripple-lib": "0.7.31",
+    "ripple-lib": "0.7.25",
     "async": "~0.2.9",
     "extend": "~1.2.0",
     "simple-jsonrpc": "~0.0.2",
@@ -31,4 +31,4 @@
   },
 
   "readmeFilename": "README.md"
-}
+}