Migrate to latest faas-provider version with namespace CRUD

Changelog for 0.26.5:

• PR #1801 feat: modernize api spec and v2 proposal by @LucasRoesler

Commits
9e6f814 Increase go.mod version by @alexellis
68ec0f5 Migrate to latest faas-provider version by @alexellis
c0d710c chore: add missing List Namespaces endpoint by @LucasRoesler
373a792 Remove generated models by @LucasRoesler
06ade37 feat: refactor api spec to use OpenAPI and add missing spec by @LucasRoesler

Changes: 0.26.4...0.26.5

Generated by Derek