✨ Add Sendy-Node (#1013)

* ✨ Sendy-Node

* ✨ Improvements

* ⚡ Small improvement

packages/nodes-base/nodes/Sendy/GenericFunctions.ts

@@ -0,0 +1,48 @@
+import {
+	OptionsWithUri,
+} from 'request';
+
+import {
+	IExecuteFunctions,
+	ILoadOptionsFunctions,
+} from 'n8n-core';
+
+import {
+	IDataObject,
+} from 'n8n-workflow';
+
+export async function sendyApiRequest(this: IExecuteFunctions | ILoadOptionsFunctions, method: string, path: string, body: any = {}, qs: IDataObject = {}, option = {}): Promise<any> { // tslint:disable-line:no-any
+
+	const credentials = this.getCredentials('sendyApi') as IDataObject;
+
+	body.api_key = credentials.apiKey;
+
+	body.boolean = true;
+
+	const options: OptionsWithUri = {
+		headers: {
+			'Content-Type': 'application/x-www-form-urlencoded',
+		},
+		method,
+		form: body,
+		qs,
+		uri: `${credentials.url}${path}`,
+	};
+
+	try {
+		//@ts-ignore
+		return await this.helpers.request.call(this, options);
+	} catch (error) {
+		if (error.response && error.response.body && error.response.body.error) {
+
+			let errors = error.response.body.error.errors;
+
+			errors = errors.map((e: IDataObject) => e.message);
+			// Try to return the error prettier
+			throw new Error(
+				`Sendy error response [${error.statusCode}]: ${errors.join('|')}`
+			);
+		}
+		throw error;
+	}
+}