Travis-CI changes.
Travis-CI changes.

- set TEST_PHP_EXECUTABLE env var
- don't apt-get libyaml (already installed)

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