[frogr] Update instructions and requirements to build a flatpak bundle

[Mario Sanchez Prada <msanchez src gnome org>]

commit 927982cdc094beb8f073107e953c821ddb55ed41
Author: Mario Sanchez Prada <msanchez gnome org>
Date:   Tue Oct 4 22:34:16 2016 +0100

    Update instructions and requirements to build a flatpak bundle
    
    Also, make the JSON file depend on the stable GNOME 3.22 release,
    which already has the required stuff in place for the OpenURI portal.

 flatpak/README.md            |   30 ++++++++++--------------------
 flatpak/org.gnome.Frogr.json |    3 +--
 2 files changed, 11 insertions(+), 22 deletions(-)
---
diff --git a/flatpak/README.md b/flatpak/README.md
index 3ecc2e0..7521eae 100644
--- a/flatpak/README.md
+++ b/flatpak/README.md
@@ -6,27 +6,29 @@ This directory contains the relevant files to build frogr as an flatpak applicat
 Requirements:
 ------------
 
-  * flatpak >= 0.5
-  * flatpak-builder >= 0.5
+  * flatpak >= 0.6.7
+  * flatpak-builder >= 0.6.7
+  * xdg-desktop-portal >= 0.1
+  * xdg-desktop-portal-gtk >= 0.1
   * appstream-composer (automatically run by flatpak-builder)
-  * org.gnome and org.freedesktop Platform and Sdk runtimes
+  * org.gnome Platform and Sdk runtimes >= 3.22
 
 Instructions:
 -------------
 
 (1) Install the flatpak repository for GNOME nightly:
 ```
-  wget -O - http://sdk.gnome.org/apt/debian/conf/alexl.gpg.key|sudo apt-key add -
-  flatpak --user remote-add --gpg-key=nightly.gpg gnome-nightly http://sdk.gnome.org/nightly/repo
+  wget https://sdk.gnome.org/keys/gnome-sdk.gpg
+  flatpak --user remote-add --gpg-import=gnome-sdk.gpg gnome http://sdk.gnome.org/repo
 ```
 (2) Install the required runtimes
 ```
-  flatpak --user install gnome-nightly org.gnome.Platform
-  flatpak --user install gnome-nightly org.gnome.Sdk
+  flatpak --user install gnome org.gnome.Platform 3.22
+  flatpak --user install gnome org.gnome.Sdk 3.22
 ```
 (3) Build frogr From this directory:
 ```
-  flatpak-builder --repo=repo frogr.appdir org.gnome.Frogr.json
+  flatpak-builder --force-clean --ccache --require-changes --repo=repo frogr.appdir org.gnome.Frogr.json
 ```
 (4) Add a remote to your local repo and install it:
 ```
@@ -47,16 +49,4 @@ Note that if you do further changes in the `appdir` (e.g. to the metadata), you'
 Last, you can bundle frogr to a file with the `build-bundle` subcommand:
 ```
   flatpak build-bundle repo frogr.bundle org.gnome.Frogr
-
-Known Issues
-------------
-
-For frogr to be useful, it needs to be able to launch your default browser to authorize your flickr account, 
which won't work at the moment since gtk_show_uri() from inside an flatpak won't be able to do that until 
there's a Portal for it.
-
-As a workaround, you can use your distribution's version of frogr to authenticate it from a normal session 
and then copy the accounts.xml file over to flatpak's realms:
-
-```
-  $ frogr # launch frogr from commandline outside flatpak, and authorize it
-  $ cp ~/.config/frogr/accounts.xml ~/.var/app/org.gnome.Frogr/config/frogr
-  $ flatpak run org.gnome.Frogr  # Now frogr should connect to your account
 ```
diff --git a/flatpak/org.gnome.Frogr.json b/flatpak/org.gnome.Frogr.json
index 5766c5f..00c85ca 100644
--- a/flatpak/org.gnome.Frogr.json
+++ b/flatpak/org.gnome.Frogr.json
@@ -1,13 +1,12 @@
 {
     "app-id": "org.gnome.Frogr",
     "runtime": "org.gnome.Platform",
-    "runtime-version": "master",
+    "runtime-version": "3.22",
     "sdk": "org.gnome.Sdk",
     "command": "frogr",
     "rename-appdata-file": "frogr.appdata.xml",
     "rename-desktop-file": "frogr.desktop",
     "tags": ["nightly"],
-    "desktop-file-name-prefix": "(Nightly) ",
     "finish-args": [
         /* X11 + XShm access */
         "--share=ipc", "--socket=x11",