Update rubytree to version 2.0.3

Author: depfu[bot]

Gemfile.lock

@@ -164,7 +164,7 @@ GEM
     irb (1.13.1)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
-    json (2.7.1)
+    json (2.7.2)
     json-jwt (1.16.6)
       activesupport (>= 4.2)
       aes_key_wrap
@@ -390,7 +390,7 @@ GEM
       mime-types (>= 3.0, < 4.0)
       oauth (>= 0.4.5)
     ruby2_keywords (0.0.5)
-    rubytree (2.0.2)
+    rubytree (2.0.3)
       json (~> 2.0, > 2.3.1)
     sawyer (0.9.2)
       addressable (>= 2.3.5)