fix mock values in btax compute.py
fix mock values in btax compute.py

OpenSourcePolicyCenter/PolicyBrain,OpenSourcePolicyCenter/webapp-public,OpenSourcePolicyCenter/PolicyBrain,OpenSourcePolicyCenter/webapp-public,OpenSourcePolicyCenter/webapp-public,OpenSourcePolicyCenter/PolicyBrain,OpenSourcePolicyCenter/PolicyBrain,OpenSourcePolicyCenter/webapp-public