Estafette-Gke-Preemptible-Killer v1.2.1

Resolved issues (3)

• Adopt new versioning strategy. #49, @JorritSalverda
• Switch to v3 logging. #46, @JorritSalverda
• Add helm value for toggling gcp-service-account annotation on secret. #45, @JorritSalverda

Resolved pull requests (3)

• use semver with auto increment in label and fixed patch version. #50, @JorritSalverda
• Fix an issue that prevents startup if filters is not set. #48, @andrei-pavel
• Use estafette foundation for v3 log format. #47, @JorritSalverda

See milestone 1.2.1 for more details.