Upgrade py-trie for v2 rlp support

Author: carver

setup.py

@@ -16,7 +16,7 @@
         "py-ecc>=1.4.7,<5.0.0",
         "pyethash>=0.1.27,<1.0.0",
         "rlp==2.0.0-alpha.1",
-        "trie==2.0.0-alpha.3",
+        "trie==2.0.0-alpha.4",
     ],
     # The eth-extra sections is for libraries that the evm does not
     # explicitly need to function and hence should not depend on.