provider/aws: Changing the tests for `aws_ssm_association` to align with

us-west-2

```
% make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSSSMAssociation_'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2016/09/02 16:56:09 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v
-run=TestAccAWSSSMAssociation_ -timeout 120m
=== RUN   TestAccAWSSSMAssociation_basic
--- PASS: TestAccAWSSSMAssociation_basic (136.23s)
PASS
ok      github.com/hashicorp/terraform/builtin/providers/aws    136.246s
```

builtin/providers/aws/resource_aws_ssm_association.go

@@ -48,21 +48,20 @@ func resourceAwsSsmAssociationCreate(d *schema.ResourceData, meta interface{}) e
 	}
 
 	if v, ok := d.GetOk("parameters"); ok {
-		assosciationInput.Parameters = expandDocumentParameters(v.(map[string]interface{}))
+		assosciationInput.Parameters = expandSSMDocumentParameters(v.(map[string]interface{}))
 	}
 
 	resp, err := ssmconn.CreateAssociation(assosciationInput)
-
 	if err != nil {
 		return errwrap.Wrapf("[ERROR] Error creating SSM association: {{err}}", err)
 	}
 
-	if resp.AssociationDescription != nil {
-		d.SetId(*resp.AssociationDescription.Name)
-	} else {
+	if resp.AssociationDescription == nil {
 		return fmt.Errorf("[ERROR] AssociationDescription was nil")
 	}
 
+	d.SetId(*resp.AssociationDescription.Name)
+
 	return resourceAwsSsmAssociationRead(d, meta)
 }
 
@@ -81,18 +80,15 @@ func resourceAwsSsmAssociationRead(d *schema.ResourceData, meta interface{}) err
 	if err != nil {
 		return errwrap.Wrapf("[ERROR] Error reading SSM association: {{err}}", err)
 	}
+	if resp.AssociationDescription == nil {
+		return fmt.Errorf("[ERROR] AssociationDescription was nil")
+	}
 
-	if resp.AssociationDescription != nil {
 	association := resp.AssociationDescription
-
 	d.Set("instance_id", association.InstanceId)
 	d.Set("name", association.Name)
 	d.Set("parameters", association.Parameters)
 
-	} else {
-		return fmt.Errorf("[ERROR] AssociationDescription was nil")
-	}
-
 	return nil
 }
 
@@ -115,7 +111,7 @@ func resourceAwsSsmAssociationDelete(d *schema.ResourceData, meta interface{}) e
 	return nil
 }
 
-func expandDocumentParameters(params map[string]interface{}) map[string][]*string {
+func expandSSMDocumentParameters(params map[string]interface{}) map[string][]*string {
 	var docParams = make(map[string][]*string)
 	for k, v := range params {
 		var values []*string

builtin/providers/aws/resource_aws_ssm_association_test.go

@@ -98,10 +98,9 @@ resource "aws_security_group" "tf_test_foo" {
 }
 
 resource "aws_instance" "foo" {
-  # eu-west-1
-  ami = "ami-f77ac884"
-  availability_zone = "eu-west-1a"
-  instance_type = "t2.small"
+  ami = "ami-4fccb37f"
+  availability_zone = "us-west-2a"
+  instance_type = "m1.small"
   security_groups = ["${aws_security_group.tf_test_foo.name}"]
 }