delete(id) {
    var _this = this;

    return new Promise((resolve, reject) => {
      if (!id) return reject(new errors.InvalidArugmentError('id is required'));

      return _this.list()
        .then((connections) => {
          return findConnectionById(id, connections)
            .then(function(connection) {
              return removeConnection(connection, connections);
            });
        })
        .then(convertConnectionInstancesIntoConfig)
        .then(writeConfigFile)
        .then(() => {
          return resolve(null);
        })
        .catch(reject);
    });
  }
Delete a connection by id
@param {string} id - id of the connection to delete