Travis: Check if icons and locales are up to date on release

.travis.yml

@@ -48,3 +48,11 @@ jobs:
       script: ./contrib/build-osx/make_osx
       after_script: ls -lah dist && md5 dist/*
       after_success: true
+    - stage: release check
+      install:
+          - git fetch --all --tags
+          - git fetch origin --unshallow
+      script:
+        - ./contrib/deterministic-build/check_submodules.sh
+      after_success: true
+      if: tag IS present

contrib/deterministic-build/check_submodules.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+
+here=$(dirname "$0")
+test -n "$here" -a -d "$here" || exit
+
+cd ${here}/../..
+
+git submodule init
+git submodule update
+
+function get_git_mtime {
+    if [ $# -eq 1 ]; then
+        git log --pretty=%at -n1 -- $1
+    else
+        git log --pretty=%ar -n1 -- $2
+    fi
+}
+
+fail=0
+
+for f in icons/* "icons.qrc"; do
+    if (( $(get_git_mtime "$f") > $(get_git_mtime "contrib/deterministic-build/electrum-icons/") )); then
+        echo "Modification time of $f (" $(get_git_mtime --readable "$f") ") is newer than"\
+             "last update of electrum-icons"
+        fail=1
+    fi
+done
+
+if [ $(date +%s -d "2 weeks ago") -gt $(get_git_mtime "contrib/deterministic-build/electrum-locale/") ]; then
+    echo "Last update from electrum-locale is older than 2 weeks."\
+         "Please update it to incorporate the latest translations from crowdin."
+    fail=1
+fi
+
+exit ${fail}