fix for PHP warning "is_file(): open_basedir restriction in effect"

Example:
PHP Warning: is_file(): open_basedir restriction in effect. File(/home/users/.../user/plugins/.gitkeep/.gitkeep.yaml) is not within the allowed path(s): (/home/users/.../:/usr/share/pear/) in .../web/system/src/Grav/Common/Config.php:237
accidental commit reverted
Getting away from providing vendor with the repo
Ignoring vendor folder
Including compohser.phar
Autorun composer install when running the grav cli
Changed command suggestion to run for installing the dependencies
Removed vendors from the mapping in SetupCommand
Merge branch 'feature/vendor_free' into develop
assets attributes implemented
PHPDocs updated
Merge pull request #46 from rindeal/feature/configurable-assets-attributes

Feature/configurable assets attributes
reverted back to file-only checks, changed to file_exists()
Merge pull request #47 from rindeal/feature/config-fixes

fix for PHP warning "is_file(): open_basedir restriction in effect"
Revert "reverted back to file-only checks, changed to file_exists()"

This reverts commit d234b8e2128356a5d7c76e7d7048c21a26bd49c2.
final workaround for PHP bug 52065
Merge pull request #48 from rindeal/feature/config-fixes

fix for PHP warning "is_file(): open_basedir restriction in effect", round 2
Fixed use of streams. Using YAML_EXT constant for the extension. Changed get and all methods to static
Merge branch 'develop' into feature/gpm
Merge branch 'develop' into feature/gpm