Test code refactor #63

Use mocha for feature-specific unit tests

Add test coverage report via istanbul

test/bench/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "sharp-benchmark",
+  "version": "0.0.1",
+  "private": true,
+  "author": "Lovell Fuller <npm@lovell.info>",
+  "description": "Benchmark and performance tests for sharp",
+  "scripts": {
+    "test": "node perf && node random && node parallel"
+  },
+  "devDependencies": {
+    "imagemagick": "^0.1.3",
+    "imagemagick-native": "^1.4.0",
+    "gm": "^1.16.0",
+    "async": "^0.9.0",
+    "benchmark": "^1.0.0"
+  },
+  "license": "Apache 2.0",
+  "engines": {
+    "node": ">=0.10"
+  }
+}