Added script to build snap locally and push to snapcraft.io candidate and edge.

Thanks to xet7 !

releases/snap-build-push-edge-candidate.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+if [ $# -ne 1 ]
+  then
+    echo "Use: snapcraft login"
+    echo "Then use version number:"
+    echo "  ./releases/snap-build-push-edge-candidate.sh 7.88"
+    exit 1
+fi
+
+sudo apt -y install snapd
+sudo systemctl enable snapd
+sudo systemctl start snapd
+sudo snap install snapcraft --classic
+sudo snap install multipass
+multipass launch --name ubu
+snapcraft
+snapcraft upload --release=candidate,edge wekan_$1_amd64.snap