Upgrade supertest + nock to recent version

The most recent version that was explicitly marked as compatible with
Node.js 0.10.x

package.json

@@ -30,8 +30,8 @@
     "istanbul": "^0.4.2",
     "lolex": "^1.5.0",
     "mocha": "^3.4.2",
-    "nock": "~1.9.0",
-    "supertest": "~0.15.0"
+    "nock": "^8.2.1",
+    "supertest": "^2.0.1"
   },
   "scripts": {
     "lint": "eslint .",
@@ -39,7 +39,7 @@
     "test-coverage": "istanbul cover ./node_modules/.bin/_mocha -- test/test.js test/test-ratelimit.js --reporter spec"
   },
   "engines": {
-    "node": ">=0.6.6",
+    "node": ">=0.10.0",
     "npm": ">=1.1.0"
   }
 }

test/test.js

@@ -165,7 +165,7 @@ describe('Basic functionality', function() {
       .expect('x-final-url', 'http://example.com/redirecttarget')
       .expect('access-control-expose-headers', /some-header,x-final-url/)
       .expectNoHeader('header at redirect')
-      .expect(200, '', done);
+      .expect(200, undefined, done);
   });
 
   it('GET with redirect should be followed', function(done) {