Changing duration types from int64 to float64

[shaheed121]

Gitlab uses float format for build related information. Since it was not documented, it could not be part of previous PR. Below snippet is from test setup.

  "build_status": "running",
  "build_started_at": "2021-01-11 20:21:22 +0100",
  "build_finished_at": null,
  "build_duration": 0.08038407,
  "build_allow_failure": false,
  "build_failure_reason": "unknown_failure",
  "pipeline_id": 33,

[shaheed121]

@Toshik1978 Could you please merge this into v6? Thanks.

[Toshik1978]

@shaheed121 will do in the nearest days! Thanks a lot, that you found it before v6 release! I thought about build_duration because of @zrochler PR, but didn't found any examples and planned to test it ) You save my time

[shaheed121]

@Toshik1978 Would you be able to make a new release? Appreciate all the help from you so far :)

[Toshik1978]

@Toshik1978 Would you be able to make a new release? Appreciate all the help from you so far :)

@shaheed121 planned to wait for final v6, but ok, will merge now. Important comment. Now the import should be done via github, not gopkg.in - we finally added support of go modules for the project.