travis: commit and push only if GH_TOKEN is set

This allows to enable travis build for a pull request without failing it.
This is useful to check at leat that Makefile syntax is correct.

.travis.yml

@@ -3,15 +3,7 @@ sudo: false
 
 script:
   - make versions.json
-  - git config --global user.email 'mxebot@gmail.com'
-  - git config --global user.name 'MXEBot as Travis CI'
-  - git config --global push.default simple
-  - git config credential.helper "store --file=.git/credentials"
-  - echo "https://${GH_TOKEN}:@github.com" > .git/credentials
-  - git remote set-url origin 'https://github.com/mxe/mxe.git'
-  - git commit -a -m 'Update versions.json' || true
-  - git push origin HEAD:master
-  - git push origin HEAD:gh-pages
+  - if [ "$GH_TOKEN" != "" ]; then ./tools/travis-push.sh; fi
 
 env:
   global:

tools/travis-push.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+set -ue
+
+git config --global user.email 'mxebot@gmail.com'
+git config --global user.name 'MXEBot as Travis CI'
+git config --global push.default simple
+git config credential.helper "store --file=.git/credentials"
+echo "https://${GH_TOKEN}:@github.com" > .git/credentials
+git remote set-url origin 'https://github.com/mxe/mxe.git'
+git commit -a -m 'Update versions.json' || true
+git push origin HEAD:master
+git push origin HEAD:gh-pages