Added keyword for role create and delete

[rohini-nubolab]

Added keyword for role create and delete

Fixes #96

[m-wcislo]

Complete checklist

At least one example testcase added in testcases/
Library Documentation regenerated according to Generate docs
All new testcases tagged as prerelease along other tags to exclude it from execution until released on PyPI
Coverage threshold increased in .coveragerc if new coverage is higher than actual, see the lint-and-coverage step in CI

[rohini-nubolab]

Complete checklist

At least one example testcase added in testcases/
Library Documentation regenerated according to Generate docs
All new testcases tagged as prerelease along other tags to exclude it from execution until released on PyPI
Coverage threshold increased in .coveragerc if new coverage is higher than actual, see the lint-and-coverage step in CI

done