ensure the test db is created if the user only runs npm test

Makefile

@@ -11,6 +11,8 @@ db:
 	@if ! [ -f test/support/big.db ]; then                                   \
 		echo "Creating test database... This may take several minutes." ;      \
 		node test/support/createdb.js ;                                        \
+	else                                                                     \
+		echo "okay: database already created" ;                                \
 	fi
 
 test: build db

package.json

@@ -36,6 +36,7 @@
         "node": ">= 0.6.13 && < 0.11.0"
     },
     "scripts": {
+        "pretest":"make db",
         "test": "mocha -R spec"
     },
     "licenses": [{ "type": "BSD" }],