update solidity-docgen

(cherry picked from commit e557a54ce77803328ce3dc1ac7d8d3c586d1c0f2)

package.json

@@ -65,7 +65,7 @@
     "openzeppelin-test-helpers": "^0.4",
     "solhint": "2.1.0",
     "solidity-coverage": "github:rotcivegaf/solidity-coverage#5875f5b7bc74d447f3312c9c0e9fc7814b482477",
-    "solidity-docgen": "^0.3.0-beta.4",
-    "truffle": "^5.0.18"
+    "solidity-docgen": "^0.3.5",
+    "truffle": "^5.0.41"
   }
 }