Updates requirements

Pipfile

@@ -9,14 +9,15 @@ plyvel = "*"
 py-solc = "*"
 coverage = "*"
 BTrees = "*"
-ethereum = "*"
+ethereum = ">=2.3.0"
-zodb = ">=*"
+zodb = ">=5.3.0"
 eth-abi = "*"
-"z3-solver" = "*"
+"z3-solver" = ">=4.5"
 eth-account = "*"
 eth-tester = "*"
-laser-ethereum = "*"
+laser-ethereum = ">=0.5.20"
 "jinja2" = "*"
+attrs = ">=17.0.0"
 
 [dev-packages]
 pylint = "*"

requirements.txt

@@ -16,3 +16,4 @@ eth-rlp>=0.1.0
 eth-tester>=0.1.0b21
 coverage
 jinja2
+attrs

setup.py

@@ -304,7 +304,8 @@ setup(
         'eth-rlp>=0.1.0',
         'eth-tester>=0.1.0b21',
         'coverage',
-        'jinja2'
+        'jinja2',
+        'attrs'
     ],
 
     python_requires='>=3.5',