Adjust build script

Should not fail on pull-request builds.

Author: k-takata

.travis.yml

@@ -12,4 +12,7 @@ env:
 
 script:
   - sh ./tools/install_sshkey_github.sh $encrypted_3ac247a44cc5_key $encrypted_3ac247a44cc5_iv ./tools/[email protected] ~/.ssh/[email protected]
-  - '[ "$TRAVIS_BRANCH" == "$DEPLOY_BRANCH" ] && [ "$TRAVIS_PULL_REQUEST" == "false" ] && sh ./tools/deploy-gh-pages.sh _gh-pages'
+  - |
+    if [ "$TRAVIS_BRANCH" = "$DEPLOY_BRANCH" ] && [ "$TRAVIS_PULL_REQUEST" = "false" ]; then
+      sh ./tools/deploy-gh-pages.sh _gh-pages
+    fi