The TagResource api call method does not seem to be available.  Get a 404 (NOT FOUND) when calling this method.
import unittest
import json
from localstack.services.awslambda import lambda_api, lambda_executors
from localstack.utils.aws.aws_models import LambdaFunction
class TestLambdaAPI(unittest.TestCase):
    CODE_SIZE = 50
    HANDLER = 'index.handler'
    RUNTIME = 'node.js4.3'
    TIMEOUT = 60  
    FUNCTION_NAME = 'test1'