Make Travis CI build build-matrix.html

Fixes #1074.

.travis.yml

@@ -2,7 +2,7 @@ language: c
 sudo: false
 
 script:
-  - make versions.json
+  - make build-matrix.html versions.json
   - if [ "$GH_TOKEN" != "" ]; then ./tools/travis-push.sh; fi
 
 env:

tools/travis-push.sh

@@ -8,6 +8,6 @@ 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 commit -a -m 'Update versions.json & build-matrix.html' || true
 git push origin HEAD:master
 git push origin HEAD:gh-pages