Add sub-minimal mocking of elasticbeanstalk:create_application()

tests/test_eb/test_eb.py

@@ -1,15 +1,39 @@
 import boto3
+import sure  # noqa
+from botocore.exceptions import ClientError
+
 from moto import mock_eb
 
 
 @mock_eb
-def test_application():
+def test_create_application():
     # Create Elastic Beanstalk Application
-    eb_client = boto3.client('elasticbeanstalk', region_name='us-east-1')
+    conn = boto3.client('elasticbeanstalk', region_name='us-east-1')
+    app = conn.create_application(
+        ApplicationName="myapp",
+    )
+    app['Application']['ApplicationName'].should.equal("myapp")
 
-    eb_client.create_application(
+
+@mock_eb
+def test_create_application_dup():
+    conn = boto3.client('elasticbeanstalk', region_name='us-east-1')
+    conn.create_application(
+        ApplicationName="myapp",
+    )
+    conn.create_application.when.called_with(
+        ApplicationName="myapp",
+    ).should.throw(ClientError)
+
+
+@mock_eb
+def test_describe_applications():
+    # Create Elastic Beanstalk Application
+    conn = boto3.client('elasticbeanstalk', region_name='us-east-1')
+    conn.create_application(
         ApplicationName="myapp",
     )
 
-    eb_apps = eb_client.describe_applications()
-    eb_apps['Applications'][0]['ApplicationName'].should.equal("myapp")
+    apps = conn.describe_applications()
+    len(apps['Applications']).should.equal(1)
+    apps['Applications'][0]['ApplicationName'].should.equal('myapp')