Make http server dev only

package.json

@@ -19,7 +19,6 @@
     "babel-runtime": "^6.3.19",
     "bignumber.js": "^2.0.3",
     "https-proxy-agent": "^1.0.0",
-    "jayson": "^1.2.2",
     "jsonschema": "^1.1.1",
     "lodash": "^3.1.0",
     "ripple-address-codec": "^2.0.1",
@@ -51,6 +50,7 @@
     "gulp-uglify": "^1.1.0",
     "http-server": "^0.8.5",
     "istanbul": "^1.1.0-alpha.1",
+    "jayson": "^1.2.2",
     "json-loader": "^0.5.2",
     "json-schema-to-markdown-table": "^0.4.0",
     "mocha": "^2.1.0",