Used a consistent tense for system messages (#8079)

app/team.go

@@ -681,7 +681,7 @@ func (a *App) postRemoveFromTeamMessage(user *model.User, channel *model.Channel
 		Type:      model.POST_REMOVE_FROM_TEAM,
 		UserId:    user.Id,
 		Props: model.StringInterface{
-			"removedUsername": user.Username,
+			"username": user.Username,
 		},
 	}
 

i18n/en.json

@@ -153,7 +153,7 @@
   },
   {
     "id": "api.channel.add_member.added",
-    "translation": "%v added to the channel by %v"
+    "translation": "%v added to the channel by %v."
   },
   {
     "id": "api.channel.add_member.find_channel.app_error",
@@ -233,7 +233,7 @@
   },
   {
     "id": "api.channel.delete_channel.archived",
-    "translation": "%v has archived the channel."
+    "translation": "%v archived the channel."
   },
   {
     "id": "api.channel.delete_channel.cannot.app_error",
@@ -297,7 +297,7 @@
   },
   {
     "id": "api.channel.join_channel.post_and_forget",
-    "translation": "%v has joined the channel."
+    "translation": "%v joined the channel."
   },
   {
     "id": "api.channel.leave.default.app_error",
@@ -313,7 +313,7 @@
   },
   {
     "id": "api.channel.leave.left",
-    "translation": "%v has left the channel."
+    "translation": "%v left the channel."
   },
   {
     "id": "api.channel.change_channel_privacy.private_to_public",
@@ -369,7 +369,7 @@
   },
   {
     "id": "api.channel.remove_member.removed",
-    "translation": "%v was removed from the channel."
+    "translation": "%v removed from the channel."
   },
   {
     "id": "api.channel.remove_member.unable.app_error",
@@ -2184,7 +2184,7 @@
   },
   {
     "id": "api.team.add_user_to_team.added",
-    "translation": "%v added to the team by %v"
+    "translation": "%v added to the team by %v."
   },
   {
     "id": "api.team.add_user_to_team.missing_parameter.app_error",
@@ -2320,7 +2320,7 @@
   },
   {
     "id": "api.team.remove_user_from_team.removed",
-    "translation": "%v was removed from the team."
+    "translation": "%v removed from the team."
   },
   {
     "id": "api.team.signup_team.email_disabled.app_error",