add support for pubsub emulator

Author: joacohoyos

Cargo.lock

@@ -62,8 +62,10 @@ openssl = { version = "0.10", optional = true, features = ["vendored"] }
 redis = { version = "0.21.6", optional = true, features = ["tokio-comp"] }
 
 # features: gcp
-google-cloud-pubsub = { version = "0.12.0", optional = true }
-google-cloud-googleapis = { version = "0.7.0", optional = true }
+
+google-cloud-gax = {version ="0.17.0", optional = true }
+google-cloud-pubsub = { version = "0.23.0", optional = true }
+google-cloud-googleapis = { version = "0.12.0", optional = true }
 
 # features: rabbitmqsink
 lapin = { version = "2.1.1", optional = true }
@@ -78,5 +80,5 @@ elasticsink = ["elasticsearch", "tokio"]
 fingerprint = ["murmur3"]
 aws = ["aws-config", "aws-sdk-sqs", "aws-sdk-lambda", "aws-sdk-s3", "tokio"]
 redissink = ["redis", "tokio"]
-gcp = ["google-cloud-pubsub", "google-cloud-googleapis", "tokio", "web"]
+gcp = ["google-cloud-pubsub", "google-cloud-googleapis", "tokio", "web" ,"google-cloud-gax"]
 rabbitmqsink = ["lapin", "tokio"]