Update the release version to 2.3.0, skipping 2.2.1

+ New feature: Add /previewpush endpoint to preview the payload that would be
  generated and sent to push services. (Issue #140)
  This helps with debugging.
+ Maintenance: Update APNS binary provider API(default) from version 1 to version 2.
+ Maintenance: Upgrade to redis.v5 (Issue #143)
+ New provider: Add FCM support. (Issue #148)
  The parameters that would be provided to /addpsp, /subscribe, and /push are
  the same as they would be for GCM. (Replace "fcm" with "gcm")
+ New feature: Add support APNS HTTP2 API (Issue #157, PR #173)
  This gives more accurate results on whether a push succeeded,
  and should not impact Uniqush's performance.
  To set this up, call /addpsp (to create a new provider or modify an
  existing provider) with the same params you would use to create a new
  APNS endpoint for binary providers (including cert and key),
  in addition to providing `bundleid`.
  Currently, to make testing easy, each call to `/push` must be provided with
  the query param value `uniqush.http=1`.
  Otherwise, uniqush continues to use the APNS binary provider API.
+ Maintenance: Use unescaped payloads for GCM and FCM.
  This allows larger payloads, avoiding escaping characters such as `<` and `>`

Fixes #134

go 1.8.3+ and an up to date version of golang.org/x/net/http2
are suggested (For the APNS HTTP2 API).

main.go

@@ -29,7 +29,7 @@ import (
 var uniqushPushConfFlags = flag.String("config", "/etc/uniqush/uniqush-push.conf", "Config file path")
 var uniqushPushShowVersionFlag = flag.Bool("version", false, "Version info")
 
-var uniqushPushVersion = "uniqush-push 2.2.1"
+var uniqushPushVersion = "uniqush-push 2.3.0"
 
 func installPushServices() {
 	srv.InstallGCM()