Merge pull request #1332 from ethereum/upgrade-pyrlp-1.0.3

Upgrade pyrlp to 1.0.3

Author: carver

setup.py

@@ -14,7 +14,7 @@
         "lru-dict>=1.1.6",
         "py-ecc>=1.4.2,<2.0.0",
         "pyethash>=0.1.27,<1.0.0",
-        "rlp>=1.0.2,<2.0.0",
+        "rlp>=1.0.3,<2.0.0",
         "trie>=1.3.5,<2.0.0",
     ],
     # The eth-extra sections is for libraries that the evm does not