Travis-CI changes.
Travis-CI changes.

- turn default notifications on
- build against 5.2-5.5
- tweak run-tests.php settings

php/pecl-file_formats-yaml,php/pecl-file_formats-yaml,Sean-Der/pecl-file_formats-yaml,bd808/pecl-file_formats-yaml,Danack/PeclYaml,bd808/pecl-file_formats-yaml,Danack/PeclYaml,Danack/PeclYaml,php/pecl-file_formats-yaml,Sean-Der/pecl-file_formats-yaml,Sean-Der/pecl-file_formats-yaml,php/pecl-file_formats-yaml,bd808/pecl-file_formats-yaml,bd808/pecl-file_formats-yaml