bump versions of package and RN components

Author: davidLeonardi

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-simple-router",
-  "version": "0.7.2",
+  "version": "0.7.3",
   "description": "Easy to use Navigator for your react-native app.",
   "author": "Tristan Edwards <tristan.edwards@me.com> (http://tristanedwards.me)",
   "contributors": [
@@ -37,7 +37,7 @@
     "underscore": "^1.8.3"
   },
   "peerDependencies": {
-    "react-native": ">=0.12.0 || 0.5.0-rc1 || 0.6.0-rc || 0.7.0-rc || 0.7.0-rc.2 || 0.8.0-rc || 0.8.0-rc.2 || 0.9.0-rc || 0.10.0-rc || 0.11.0-rc || 0.12.0-rc || 0.13.0-rc || 0.14.0-rc || 0.15.0-rc || 0.16.0-rc || 0.17.0-rc || 0.18.0-rc || 0.19.0-rc || 0.20.0-rc || 0.20.0-rc1"
+    "react-native": ">=0.12.0 || 0.5.0-rc1 || 0.6.0-rc || 0.7.0-rc || 0.7.0-rc.2 || 0.8.0-rc || 0.8.0-rc.2 || 0.9.0-rc || 0.10.0-rc || 0.11.0-rc || 0.12.0-rc || 0.13.0-rc || 0.14.0-rc || 0.15.0-rc || 0.16.0-rc || 0.17.0-rc || 0.18.0-rc || 0.19.0-rc || 0.20.0-rc || 0.20.0-rc1 || 0.21.0-rc"
   },
   "devDependencies": {
     "eslint": "^1.10.3",