add test for invalid engine version

bin/test

@@ -35,6 +35,11 @@ testPackageJsonWithoutVersion() {
   assertCapturedSuccess
 }
 
+testPackageJsonWithInvalidVersion() {
+  compile "package-json-invalidversion"
+  assertCapturedError 1 "Requested engine npm version 1.1.5 does not"
+}
+
 testNothingCached() {
   cache=$(mktmpdir)
   compile "package-json-version" $cache

test/package-json-invalidversion/package.json

+{
+  "name": "myapp",
+  "version": "0.0.1",
+
+  "engines": {
+    "node": "0.6.11",
+    "npm": "1.1.5"
+  }
+}