fix typos

Author: pacrob

Diff for: tests/frontier/opcodes/test_calldatacopy.py

@@ -142,7 +142,7 @@ def test_calldatacopy(
     """
     Test `CALLDATACOPY` opcode.
 
-    Based on https://github.com/ethereum/tests/blob/ae4791077e8fcf716136e70fe8392f1a1f1495fb/src/GeneralStateTestsFiller/VMTests/vmTests/calldatacopyFiller.ym
+    Based on https://github.com/ethereum/tests/blob/ae4791077e8fcf716136e70fe8392f1a1f1495fb/src/GeneralStateTestsFiller/VMTests/vmTests/calldatacopyFiller.yml
     """
     code_address = pre.deploy_contract(code)
     to = pre.deploy_contract(

Diff for: tests/frontier/opcodes/test_calldataload.py

@@ -70,7 +70,7 @@ def test_calldataload(
     """
     Test `CALLDATALOAD` opcode.
 
-    Based on https://github.com/ethereum/tests/blob/ae4791077e8fcf716136e70fe8392f1a1f1495fb/src/GeneralStateTestsFiller/VMTests/vmTests/calldatacopyFiller.ym
+    Based on https://github.com/ethereum/tests/blob/ae4791077e8fcf716136e70fe8392f1a1f1495fb/src/GeneralStateTestsFiller/VMTests/vmTests/calldatacopyFiller.yml
     """
     address_a = pre.deploy_contract(code_for_address_a)