Default format for gherkin tags

[delatrie]

I'm submitting a ...

• bug report
• feature request
• support request => Please do not submit support request here, see note at the top of this template.

What is the current behavior?

If no allureConfig.json with tag patterns specified in it, all gherkin tags are converted to Allure tags.

What is the expected behavior?

We should provide reasonable defaults. For example, we might convert allure.suite:My-suite to the label suite=My-suite.

What is the motivation / use case for changing the behavior?

The motivation is to make the tags API of Allure SpecFlow usable without configuration.

Please tell us about your environment:

• Allure version: 2.1.0
• Test framework: testng@6.8
• Allure adaptor: allure-testng@2.0-BETA8
• Generate report using: allure-maven@2.18

Other information

That will be a breaking change. We might provide a feature switch in allureConfig.json for those who don't want default patterns for some reasons.