[testing] data source acc test (#340)

Add an acceptance test for our 1 data source.

## Test Plan
* [ ] acceptance tests

pkg/datasources/system_get_aws_sns_iam_policy_acceptance_test.go

@@ -0,0 +1,44 @@
+package datasources_test
+
+import (
+	"testing"
+
+	"github.com/chanzuckerberg/terraform-provider-snowflake/pkg/provider"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+)
+
+// FIXME refactor to testhelpers
+func providers() map[string]*schema.Provider {
+	p := provider.Provider()
+	return map[string]*schema.Provider{
+		"snowflake": p,
+	}
+}
+
+func TestAccSystemGetAWSSNSIAMPolicy_basic(t *testing.T) {
+	// r := require.New(t)
+
+	resource.ParallelTest(t, resource.TestCase{
+		Providers: providers(),
+		Steps: []resource.TestStep{
+			{
+				Config: policyConfig(),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr("data.snowflake_system_get_aws_sns_iam_policy.p", "aws_sns_topic_arn", "arn:aws:sns:us-east-1:1234567890123456:mytopic"),
+					resource.TestCheckResourceAttr("data.snowflake_system_get_aws_sns_iam_policy.p", "aws_sns_topic_policy_json",
+						`{"Version":"2012-10-17","Statement":[{"Sid":"1","Effect":"Allow","Principal":{"AWS":"arn:aws:iam::494544507972:user/3gmi-s-ssca3411"},"Action":["sns:Subscribe"],"Resource":["arn:aws:sns:us-east-1:1234567890123456:mytopic"]}]}`),
+				),
+			},
+		},
+	})
+}
+
+func policyConfig() string {
+	s := `
+	data snowflake_system_get_aws_sns_iam_policy p {
+		aws_sns_topic_arn = "arn:aws:sns:us-east-1:1234567890123456:mytopic"
+	}
+	`
+	return s
+}