Add support for Openstack Advisories

[Samk1710]

Resolves:

• Add support for Open Stack Advisories (OSSA) #183

Added from_ossa_native function and its corresponding unit test.

Unit test logs:

collected 4661 items / 4645 deselected / 16 selected                                                 

tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[ ~= 0.9-False-Unsupported PyPI version constraint operator] PASSED [  6%]
tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[~= 1.3-False-Unsupported PyPI version constraint operator] PASSED [ 12%]
tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[ >= 1.0-True-vers:pypi/>=1.0] PASSED [ 18%]
tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[ != 1.3.4.*-False-Unsupported PyPI version] PASSED [ 25%]
tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[< 2.0-True-vers:pypi/<2.0] PASSED [ 31%]
tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[~= 1.3.4.*-False-] PASSED [ 37%]
tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[==1. *-False-Unsupported PyPI version] PASSED [ 43%]
tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[==1.3.4 ) (-False-Unsupported character] PASSED [ 50%]
tests/test_version_range.py::test_PypiVersionRange_raises_ivr_for_unsupported_and_invalid_ranges[===1.0-False-Unsupported PyPI version] PASSED [ 56%]
tests/test_version_range.py::test_PypiVersionRange_from_ossa_native[<=5.0.3, >=6.0.0 <=6.1.0 and ==7.0.0-vers:pypi/<=5.0.3|>=6.0.0|<=6.1.0|7.0.0] PASSED [ 62%]
tests/test_version_range.py::test_PypiVersionRange_from_ossa_native[<=14.0.10, >=15.0.0 <=15.0.8, >=16.0.0 <=16.0.3-vers:pypi/<=14.0.10|>=15.0.0|<=15.0.8|>=16.0.0|<=16.0.3] PASSED [ 68%]
tests/test_version_range.py::test_PypiVersionRange_from_ossa_native[<17.0.12, >=18.0.0 <18.2.2, >=19.0.0 <19.0.2-vers:pypi/<17.0.12|>=18.0.0|<18.2.2|>=19.0.0|<19.0.2] PASSED [ 75%]
tests/test_version_range.py::test_PypiVersionRange_from_ossa_native[<19.3.1, >=20.0.0 <20.3.1, ==21.0.0-vers:pypi/<19.3.1|>=20.0.0|<20.3.1|21.0.0] PASSED [ 81%]
tests/test_version_range.py::test_PypiVersionRange_from_ossa_native[>=10.5.0 <10.7.2, >=10.8.0 <10.9.1, >=10.10.0 <10.12.1-vers:pypi/>=10.5.0|<10.7.2|>=10.8.0|<10.9.1|>=10.10.0|<10.12.1] PASSED [ 87%]
tests/test_version_range.py::test_PypiVersionRange_from_ossa_native[<16.3.3, >=17.0.0 <17.1.3, =18.0.0-vers:pypi/<16.3.3|>=17.0.0|<17.1.3|18.0.0] PASSED [ 93%]
tests/test_version_range.py::test_PypiVersionRange_from_ossa_native[-InvalidVersionRange] PASSED [100%]

========================== 16 passed, 4645 deselected, 54 warnings in 0.20s ==========================

Took some inspiration from from_gitlab_native function.