Sheriff-O-Matic: Merge and update READMEs, add makefile for testing.

Tools/GardeningServer/makefile

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+NPM_VERSION := $(shell npm --version 2>/dev/null)
+BOWER_VERSION := $(shell bower --version 2>/dev/null)
+
+check:
+ifndef NPM_VERSION
+        $(error npm not found. Install from nodejs.org or see README-mocha)
+endif
+ifndef BOWER_VERSION
+        @echo "bower not found. Installing:";
+        npm install -g bower
+endif
+
+update: check
+        bower update
+        npm update
+
+test: check
+        xvfb-run ./node_modules/karma/bin/karma start
+
+single-test: check
+        xvfb-run ./node_modules/karma/bin/karma start --single-run
+
+.PHONY: check update test single-test