Bump to rc1

Author: mhadam

package.json

@@ -1,11 +1,11 @@
 {
   "name": "snowplow-tracker",
-  "version": "2.9.1",
+  "version": "2.9.1-rc1",
   "dependencies": {
     "browser-cookie-lite": "0.3.1",
     "jstimezonedetect": "1.0.5",
     "lodash": "3.10.1",
-    "snowplow-tracker-core": "0.6.1",
+    "snowplow-tracker-core": "0.6.1-beta1",
     "murmurhash": "0.0.2",
     "uuid": "2.0.3",
     "sha1": "git://github.com/pvorb/node-sha1.git#910081c83f3661507d9d89e66e3f38d8b59d5559"