add TypeScript validation

Author: eli-darkly

test-types.ts

@@ -1,3 +1,21 @@
 
 // This file exists only so that we can run the TypeScript compiler in the CI build
 // to validate our index.d.ts file.
+
+import DynamoDBFeatureStore, { LDDynamoDBOptions } from 'launchdarkly-node-server-sdk-dynamodb';
+import { LDLogger } from 'launchdarkly-node-server-sdk';
+import { DynamoDB } from 'aws-sdk';
+
+var emptyOptions: LDDynamoDBOptions = {};
+
+var ddbOptions: DynamoDB.DocumentClient.DocumentClientOptions = {};
+var ddbClient: DynamoDB.DocumentClient = new DynamoDB.DocumentClient();
+var logger: LDLogger = { error: () => {}, warn: () => {}, info: () => {}, debug: () => {} };
+
+var options: LDDynamoDBOptions = {
+	clientOptions: ddbOptions,
+	dynamoDBClient: ddbClient,
+	prefix: 'x',
+	cacheTTL: 30,
+	logger: logger
+};