add GH-workflow: php ci

[jkowalleck]

part of #86 for #123

• added the existing php tests as a GitHub workflow
• slight fixes and extensibility-modifications to existing php test-setup

☝️ PHP CI is currently failing, since some JSON schema files are not entirely valid/plausible - which is topic of #83/#123
this might be fixed via (#84/#125/...) - #124
as soon as the JSON schema files were fixed, they will pass.
Then these test can act as a gatekeeper.

[jkowalleck]

updated the test and pointed the PR to master,
in preparation for #123

[jkowalleck]

this PR detechts and chcks the relevant issues from #123

logs show only the first error for each file - example:

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.2-strict.schema.json
SCHEMA ERROR: Duplicate schema id: http://cyclonedx.org/schema/bom-1.2a.schema.json#/properties/components

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.2.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.3-strict.schema.json
SCHEMA ERROR: Duplicate schema id: http://cyclonedx.org/schema/bom-1.3.schema.json#/properties/components

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.3.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.4.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/jsf-0.82.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/spdx.schema.json
OK.

https://github.com/CycloneDX/specification/runs/5067469700?check_suite_focus=true#step:5:7

[stevespringett]

Whats the status of this PR?

[jkowalleck]

implementation tests all the JSON schema files.
the PR is ready for merge,

the github action "PHP CI" will fail, as long/soon as the json schema files are invalid.

once again rebased onto latest master.
latest output shows, that all schema fiiles are fine, now: https://github.com/CycloneDX/specification/runs/5445435252?check_suite_focus=true#step:5:7

> @php -f json-schema-lint-tests.php --

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.2-strict.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.2.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.3-strict.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.3.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/bom-1.4.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/jsf-0.82.schema.json
OK.

SchemaFile: /home/runner/work/specification/specification/tools/src/test/php/../../../../schema/spdx.schema.json
OK.