Update the parser's version after publish 0.5.0 for onap

Update the parser's version after publish 0.5.0 for onap

1. git tag 0.5.0   git push origin 0.5.0
2. set apigateway version empty
   set toscaparser version empty
   set heat-translator version empty
   version management use git tag, note: tag name must be started with
digit

JIRA: PARSER-147

Change-Id: I71cc9b910bce57eebf4c07976bd24efd441048fa
Signed-off-by: shangxdy <shang.xiaodong@zte.com.cn>