ci: fix netlify build issues with babel (#1473)

- netlify build has issues with babel
- nvmrc to use latest lts in netlify
- bump babel/webpack dependencies in examples as well (need preset 7.9.0+)

Author: acao

.nvmrc

@@ -1 +1 @@
-lts/stable
+lts/erbium

examples/graphiql-webpack/package.json

@@ -16,18 +16,18 @@
     "react": "16.13.1"
   },
   "devDependencies": {
-    "@babel/plugin-proposal-class-properties": "7.7.4",
-    "@babel/plugin-syntax-dynamic-import": "7.8.3",
-    "@babel/preset-env": "7.8.3",
-    "@babel/preset-react": "7.8.3",
-    "babel-loader": "^8.0.6",
-    "cross-env": "^7.0.0",
-    "css-loader": "3.4.2",
-    "html-webpack-plugin": "^3.2.0",
+    "@babel/plugin-proposal-class-properties": "^7.8.3",
+    "@babel/plugin-syntax-dynamic-import": "^7.8.3",
+    "@babel/preset-env": "^7.9.5",
+    "@babel/preset-react": "^7.9.4",
+    "babel-loader": "^8.1.0",
+    "cross-env": "^7.0.2",
+    "css-loader": "^3.5.1",
+    "html-webpack-plugin": "^4.2.0",
     "react-dom": "^16.12.0",
-    "style-loader": "^1.1.2",
+    "style-loader": "^1.1.3",
     "webpack": "4.42.0",
-    "webpack-cli": "^3.3.10",
-    "webpack-dev-server": "^3.10.1"
+    "webpack-cli": "^3.3.11",
+    "webpack-dev-server": "^3.10.3"
   }
 }

netlify.toml

@@ -1,5 +1,5 @@
 [build]
-  command = "yarn build && yarn build-bundles && yarn build-demo && yarn build-docs"
+  command = "yarn build && yarn build-bundles && yarn build-demo"
   publish = "packages/graphiql"