Added declaration files for gramps rest-helpers

Why did you do this?

The package doesn't have it's own so I'm adding them. I don't use all of
the methods in the GraphQLConnector class, so I haven't validated that
all of these methods work, but based on the comments in the source code
it appears to be the correct types.

types/gramps__rest-helpers/gramps__rest-helpers-tests.ts

@@ -0,0 +1,16 @@
+import { GraphQLConnector, GraphQLModel } from '@gramps/rest-helpers';
+
+const myConnector = new GraphQLConnector();
+
+myConnector.apiBaseUri = "some uri";
+myConnector.headers = {};
+myConnector.cacheExpiry = 300;
+myConnector.enableCache = true;
+myConnector.redis = false;
+
+myConnector.get("someurl");
+myConnector.post("someendpoint", {}, {}).then(() => {});
+myConnector.put("someendpoint", {}, {}).then(() => {});
+myConnector.delete("someendpoint", {}).then(() => {});
+
+const myModel = new GraphQLModel(myConnector);

types/gramps__rest-helpers/index.d.ts

@@ -0,0 +1,26 @@
+// Type definitions for @gramps/rest-helpers 1.1
+// Project: https://github.com/gramps-graphql/rest-helpers
+// Definitions by: Claude Ciocan <https://github.com/claude>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+export class GraphQLConnector {
+    constructor();
+
+    apiBaseUri: string;
+    headers: object;
+    request: any;
+    cacheExpiry: number;
+    enableCache: boolean;
+    redis: boolean;
+    get(endpoint: string): Promise<any>;
+    post(endpoint: string, body: object, options: object): Promise<any>;
+    put(endpoint: string, body: object, options: object): Promise<any>;
+    delete(endpoint: string, options: object): Promise<any>;
+}
+
+export class GraphQLModel {
+    connector: GraphQLConnector;
+
+    constructor({});
+}

types/gramps__rest-helpers/tsconfig.json

@@ -0,0 +1,24 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true,
+        "paths": {
+            "@gramps/rest-helpers": [
+                "gramps__rest-helpers"
+            ]
+        }
+    }
+}

types/gramps__rest-helpers/tslint.json

@@ -0,0 +1,3 @@
+{
+    "extends": "dtslint/dt.json"
+}