Add auto-formatting to client and server modules

One thing that can make linting faster is auto-formatting. This commit
adds the yapf auto-formatting tool to the server module and uses
eslint's "fix" functionality to speed up the linting/formatting process.

client/Makefile

@@ -6,6 +6,10 @@ install:
 build: install
 	npm run build
 
+.PHONY: fmt
+fmt:
+	npm run fmt
+
 .PHONY: clean
 clean:
 	rm -rf node_modules

client/package.json

@@ -11,6 +11,7 @@
     "clean": "rimraf build",
     "dev": "npm run clean && webpack --config configuration/webpack/webpack.config.dev.js",
     "e2e": "node node_modules/jest/bin/jest.js --verbose false --config __tests__/e2e/e2eJestConfig.json e2e/e2e.test.js",
+    "fmt": "eslint --fix src",
     "lint": "eslint src",
     "smoke-test": "start-server-and-test start-server-for-test :5000 e2e",
     "start": "node server/development.js",