Adding changelog

fastlane/metadata/android/en-US/changelogs/51.txt

@@ -0,0 +1,13 @@
+* Update Spanish strings.xml (PR #116 by Pablohn26)
+* Add unit testing (enhancment #115)
+* Permission error trying to restore backup (bug #113)
+* mislabled dialog (delete time) (bug #96)
+* Vibration is initially enabled, but preferences screen says it is disabled (bug #13)
+* Initial help reappears when rotating etc. (bug #8)
+* Export view to CSV success message states wrong filename (often, not always) (bug #28)
+* Call to static SimpleDateFormat (bug #109)
+* Fix source code warnings (enhancement #110)
+* Possible to rename an acitivity to an empty name (bug #111)
+* Possible to add activity without name (bug #108)
+* Terminology change; tasks --> activities bug (enhancement #77)
+* Incorrect link for reporting bugs in docs/timetracker.rst (bug #69)