Add yet-another-react-lightbox package and update .gitignore to exclude node_modules

frontend/node_modules/ajv/lib/compile/error_classes.js

@@ -1,34 +0,0 @@
-'use strict';
-
-var resolve = require('./resolve');
-
-module.exports = {
-  Validation: errorSubclass(ValidationError),
-  MissingRef: errorSubclass(MissingRefError)
-};
-
-
-function ValidationError(errors) {
-  this.message = 'validation failed';
-  this.errors = errors;
-  this.ajv = this.validation = true;
-}
-
-
-MissingRefError.message = function (baseId, ref) {
-  return 'can\'t resolve reference ' + ref + ' from id ' + baseId;
-};
-
-
-function MissingRefError(baseId, ref, message) {
-  this.message = message || MissingRefError.message(baseId, ref);
-  this.missingRef = resolve.url(baseId, ref);
-  this.missingSchema = resolve.normalizeId(resolve.fullPath(this.missingRef));
-}
-
-
-function errorSubclass(Subclass) {
-  Subclass.prototype = Object.create(Error.prototype);
-  Subclass.prototype.constructor = Subclass;
-  return Subclass;
-}