Merge pull request #636 from tuncer/fix-634

Fix #634
diff --git a/.travis.yml b/.travis.yml
index 9589806..7af5258 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,6 +11,7 @@
   - 17.0
   - 18.0
   - 19.1
+  - 20.0.2
 before_script:
   - hostname -f
   - cc -v
diff --git a/src/rebar_core.erl b/src/rebar_core.erl
index 6cc8d38..747fe97 100644
--- a/src/rebar_core.erl
+++ b/src/rebar_core.erl
@@ -190,8 +190,8 @@
                  WouldCd);
 skip_or_process_dir(Dir, Command, Config, DirSet, CurrentCodePath,
                     {_, File}=ModuleSet, WouldCd) ->
-    case lists:suffix(".app.src", File)
-        orelse lists:suffix(".app", File) of
+    case lists:suffix(".app", File)
+        orelse rebar_app_utils:is_app_src(File) of
         true ->
             %% .app or .app.src file, check if is_skipped_app
             skip_or_process_dir1(Dir, Command, Config, DirSet, CurrentCodePath,