fix(package): update react-bootstrap to version 0.31.2

Author: greenkeeper[bot]

package.json

@@ -102,7 +102,7 @@
     "bootstrap-sass": "3.3.7",
     "material-ui": "0.18.7",
     "microformat-node": "2.0.1",
-    "react-bootstrap": "0.31.1",
+    "react-bootstrap": "0.31.2",
     "react-dom": "15.6.0",
     "react-router": "3.0.5",
     "react-router-bootstrap": "0.23.2"