Adapt preset names for babel 7

--- a/regexp-tree/.babelrc
+++ b/regexp-tree/.babelrc
@@ -3,14 +3,14 @@
     "production": {
       "presets": [
         [
-          "env",
+          "@babel/env",
           {
             "targets": {
               "node": "0.12"
             }
           }
         ],
-        "flow"
+        "@babel/flow"
       ]
     }
   }