Fix development notes.

Fix issue with react-codemirror2.

docs/devnotes.md

@@ -2,12 +2,15 @@
 
 ## Frontend
 
+### Preact
 - using [preact](https://github.com/developit/preact) for a smaller setup that 
     is compatible with React.
 - [importing preact into modules](https://github.com/developit/preact#import-what-you-need)
 - using [preact-compat](https://www.npmjs.com/package/preact-compat) to avoid 
     migrating all of React code to preact.
 - [server side rendering in preact](http://thecodebarbarian.com/server-side-rendering-with-preact-and-firebase.html)
+
+### Webpack
 - use `process.env.MY_FLAG' using 
   [webpack's DefinePlugin to pass in envs](https://webpack.js.org/plugins/define-plugin/#feature-flags).
     - this is useful when dealing with separating server-only and client-only code.

package.json

@@ -33,7 +33,7 @@
     "prop-types": "^15.5.10",
     "react": "^15.6.1",
     "react-bootstrap": "^0.31.3",
-    "react-codemirror2": "^1.1.1",
+    "react-codemirror2": "^2.0.0",
     "react-dom": "^15.6.1",
     "react-fontawesome": "^1.1.0",
     "react-redux": "^5.0.6",

yarn.lock

@@ -4977,9 +4977,9 @@ react-bootstrap@^0.31.3:
     uncontrollable "^4.1.0"
     warning "^3.0.0"
 
-react-codemirror2@^1.1.1:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/react-codemirror2/-/react-codemirror2-1.1.1.tgz#3fbb42bd2109d20eda7ae2072d1773fb75abc226"
+react-codemirror2@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/react-codemirror2/-/react-codemirror2-2.0.0.tgz#25eceff9725a2ab9e47f78fe9a23cb3923d1766e"
 
 react-dom@^15.6.1:
   version "15.6.1"