.travis.yml: split long command [ci skip]

* .travis.yml (before_script): split long command to merge pull
  requests to rubyspec from github.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58274 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

.travis.yml

@@ -47,10 +47,12 @@ before_script:
   - "make after-update BASERUBY=ruby UNICODE_FILES=."
   - "make -s $JOBS"
   - "make update-rubyspec"
-  - "${RUBYSPEC_PULL_REQUEST:+git -C spec/rubyspec -c user.email=none -c user.name=none
-      pull --no-edit origin $(for rev in ${RUBYSPEC_PULL_REQUEST//,/ }; do
-        echo +refs/pull/$rev/merge:;
-    done)}"
+  - "if [ -n \"${RUBYSPEC_PULL_REQUEST}\" ]\n
+    then\n
+      merge=\n
+      for rev in ${RUBYSPEC_PULL_REQUEST//,/ }; do merge=\"$merge +refs/pull/$rev/merge:\"; done\n
+      git -C spec/rubyspec -c user.email=none -c user.name=none pull --no-edit origin $merge\n
+    fi"
 
 script:
   - "make -s test TESTOPTS=--color=never"