Reset mtime of all files on osx

Often checked out files are in the future on OSX image.

.travis.yml

@@ -341,6 +341,8 @@ env:
       - TEST_ALL_ISOLATED_TESTS="../test/ruby/test_gc_compact.rb"
       # Disabling -j3 because it seems to cause a hang on building Ruby: https://travis-ci.org/ruby/ruby/jobs/471021727
       - JOBS=
+      # Reset timestamps earily, before updating Homebrew etc.
+      - _=$(touch NEWS && find . -type f -exec touch -r NEWS {} +)
 
   - &dependency
     name: Check dependencies in makefiles
@@ -420,12 +422,8 @@ before_script:
   - "> config.status"
   - "> .rbconfig.time"
   - sed -f tool/prereq.status template/Makefile.in common.mk > Makefile
-  - |-
-    for i in 1 2 3; do
-      date; make touch-unicode-files || break
-      ls -ltT tool/generic_erb.rb template/unicode_norm_gen.tmpl enc/unicode/data/*/ucd/.unicode-tables.time
-      date; make -s $JOBS $UPDATE_UNICODE up && break
-    done
+  - date; make touch-unicode-files
+  - date; make -s $JOBS $UPDATE_UNICODE up
   - date; make -s $JOBS srcs
   - rm -f config.status Makefile rbconfig.rb .rbconfig.time
   - |-