Also test for gql files

Created by: Findiglay

The graphhql-tag/loader test case should be extended to include .gql files which allow import of operations by name.

{
  test: /\.(graphql|gql)$/,
  loader: 'graphql-tag/loader',
},

See: https://github.com/apollographql/graphql-tag#webpack-preprocessing-with-graphql-tagloader