Fix for moto not unmocking.

- Fixes #2575
- Also upgraded Travis CI to make use of Bionic instead of Xenial
- This may also address concerns raised in #1793

tests/test_awslambda/test_lambda.py

@@ -1001,10 +1001,10 @@ def test_list_versions_by_function_for_nonexistent_function():
 @mock_lambda
 @mock_sqs
 def test_create_event_source_mapping():
-    sqs = boto3.resource("sqs")
+    sqs = boto3.resource("sqs", region_name="us-east-1")
     queue = sqs.create_queue(QueueName="test-sqs-queue1")
 
-    conn = boto3.client("lambda")
+    conn = boto3.client("lambda", region_name="us-east-1")
     func = conn.create_function(
         FunctionName="testFunction",
         Runtime="python2.7",
@@ -1030,11 +1030,11 @@ def test_create_event_source_mapping():
 @mock_lambda
 @mock_sqs
 def test_invoke_function_from_sqs():
-    logs_conn = boto3.client("logs")
-    sqs = boto3.resource("sqs")
+    logs_conn = boto3.client("logs", region_name="us-east-1")
+    sqs = boto3.resource("sqs", region_name="us-east-1")
     queue = sqs.create_queue(QueueName="test-sqs-queue1")
 
-    conn = boto3.client("lambda")
+    conn = boto3.client("lambda", region_name="us-east-1")
     func = conn.create_function(
         FunctionName="testFunction",
         Runtime="python2.7",
@@ -1054,7 +1054,7 @@ def test_invoke_function_from_sqs():
     assert response["EventSourceArn"] == queue.attributes["QueueArn"]
     assert response["State"] == "Enabled"
 
-    sqs_client = boto3.client("sqs")
+    sqs_client = boto3.client("sqs", region_name="us-east-1")
     sqs_client.send_message(QueueUrl=queue.url, MessageBody="test")
     start = time.time()
     while (time.time() - start) < 30:
@@ -1081,8 +1081,8 @@ def test_invoke_function_from_sqs():
 @mock_lambda
 @mock_dynamodb2
 def test_invoke_function_from_dynamodb():
-    logs_conn = boto3.client("logs")
-    dynamodb = boto3.client("dynamodb")
+    logs_conn = boto3.client("logs", region_name="us-east-1")
+    dynamodb = boto3.client("dynamodb", region_name="us-east-1")
     table_name = "table_with_stream"
     table = dynamodb.create_table(
         TableName=table_name,
@@ -1094,7 +1094,7 @@ def test_invoke_function_from_dynamodb():
         },
     )
 
-    conn = boto3.client("lambda")
+    conn = boto3.client("lambda", region_name="us-east-1")
     func = conn.create_function(
         FunctionName="testFunction",
         Runtime="python2.7",
@@ -1141,11 +1141,11 @@ def test_invoke_function_from_dynamodb():
 @mock_lambda
 @mock_sqs
 def test_invoke_function_from_sqs_exception():
-    logs_conn = boto3.client("logs")
-    sqs = boto3.resource("sqs")
+    logs_conn = boto3.client("logs", region_name="us-east-1")
+    sqs = boto3.resource("sqs", region_name="us-east-1")
     queue = sqs.create_queue(QueueName="test-sqs-queue1")
 
-    conn = boto3.client("lambda")
+    conn = boto3.client("lambda", region_name="us-east-1")
     func = conn.create_function(
         FunctionName="testFunction",
         Runtime="python2.7",
@@ -1201,10 +1201,10 @@ def test_invoke_function_from_sqs_exception():
 @mock_lambda
 @mock_sqs
 def test_list_event_source_mappings():
-    sqs = boto3.resource("sqs")
+    sqs = boto3.resource("sqs", region_name="us-east-1")
     queue = sqs.create_queue(QueueName="test-sqs-queue1")
 
-    conn = boto3.client("lambda")
+    conn = boto3.client("lambda", region_name="us-east-1")
     func = conn.create_function(
         FunctionName="testFunction",
         Runtime="python2.7",
@@ -1233,10 +1233,10 @@ def test_list_event_source_mappings():
 @mock_lambda
 @mock_sqs
 def test_get_event_source_mapping():
-    sqs = boto3.resource("sqs")
+    sqs = boto3.resource("sqs", region_name="us-east-1")
     queue = sqs.create_queue(QueueName="test-sqs-queue1")
 
-    conn = boto3.client("lambda")
+    conn = boto3.client("lambda", region_name="us-east-1")
     func = conn.create_function(
         FunctionName="testFunction",
         Runtime="python2.7",
@@ -1263,10 +1263,10 @@ def test_get_event_source_mapping():
 @mock_lambda
 @mock_sqs
 def test_update_event_source_mapping():
-    sqs = boto3.resource("sqs")
+    sqs = boto3.resource("sqs", region_name="us-east-1")
     queue = sqs.create_queue(QueueName="test-sqs-queue1")
 
-    conn = boto3.client("lambda")
+    conn = boto3.client("lambda", region_name="us-east-1")
     func1 = conn.create_function(
         FunctionName="testFunction",
         Runtime="python2.7",
@@ -1307,10 +1307,10 @@ def test_update_event_source_mapping():
 @mock_lambda
 @mock_sqs
 def test_delete_event_source_mapping():
-    sqs = boto3.resource("sqs")
+    sqs = boto3.resource("sqs", region_name="us-east-1")
     queue = sqs.create_queue(QueueName="test-sqs-queue1")
 
-    conn = boto3.client("lambda")
+    conn = boto3.client("lambda", region_name="us-east-1")
     func1 = conn.create_function(
         FunctionName="testFunction",
         Runtime="python2.7",