Travis : Migrating from legacy - GH-115

Author: Progi1984

.travis.yml

@@ -26,7 +26,7 @@ addons:
 before_script:
   ## Composer
   - composer self-update
-  - composer install --prefer-source --dev
+  - composer install --prefer-source
   ## PHPDocumentor
   - mkdir -p build/docs
   - mkdir -p build/coverage

CHANGELOG.md

@@ -17,6 +17,7 @@
 - PhpOffice\PhpPowerpoint\DocumentLayout::setLayoutXmilli has been removed : setCX(DocumentLayout::UNIT_MILLIMETER) - @Progi1984
 - PhpOffice\PhpPowerpoint\DocumentLayout::setLayoutYmilli has been removed : setCY(DocumentLayout::UNIT_MILLIMETER) - @Progi1984
 - Update the dependence PhpOffice\Common to 0.2.* - @Progi1984
+- Migrated Travis CI to legacy - @Progi1984 GH-115
 
 ## 0.4.0 - 2015-07-07