Fix eslint

* Ignore jupyterlab_widgets labextension
* Fix eslint config of jupyterlab_widgets to be consistent with top level
* Add some parser options so that eslint can find the correct tsconfig file.

Author: jasongrout

.eslintignore

@@ -24,6 +24,7 @@ npm-debug.log
 !.vscode/extensions.json
 
 widgetsnbextension/widgetsnbextension/static
+jupyterlab_widgets/jupyterlab_widgets/labextension/
 
 index.built.js
 index.built.js.map

.gitignore

@@ -7,8 +7,9 @@ module.exports = {
   ],
   parser: '@typescript-eslint/parser',
   parserOptions: {
-    project: 'tsconfig.json',
-    sourceType: 'module'
+    project: './tsconfig.json',
+    sourceType: 'module',
+    tsconfigRootDir: __dirname
   },
   plugins: ['@typescript-eslint'],
   rules: {
@@ -20,6 +21,8 @@ module.exports = {
     '@typescript-eslint/no-explicit-any': 'off',
     '@typescript-eslint/no-namespace': 'off',
     '@typescript-eslint/no-use-before-define': 'off',
+    '@typescript-eslint/camelcase': 'off',
+    '@typescript-eslint/no-non-null-assertion': 'off',
     '@typescript-eslint/quotes': [
       'error',
       'single',