remove null-safe version suffix

Author: TatsuUkraine

CHANGELOG.md

@@ -1,4 +1,4 @@
-## [3.0.0-nullsafety.0] - 26.04.2021
+## [3.0.0] - 26.04.2021
 
 - migrate to null-safe
 

pubspec.yaml

@@ -1,6 +1,6 @@
 name: environment_config
 description: Environment specific config generator. Allows to specify env configuration during CI/CD build. Primarily created to simplify Flutter build configuration
-version: 3.0.0-nullsafety.0
+version: 3.0.0
 homepage: https://github.com/TatsuUkraine/dart_environment_config
 repository: https://github.com/TatsuUkraine/dart_environment_config
 issue_tracker: https://github.com/TatsuUkraine/dart_environment_config/issues