Add @ApiResponse tags in controller classes already implemented (techs, users, teams, sprints, auth)

### Add @Api Response tags to controller classes that are missing this tag. #### This is a part of maintaining API endpoints documentation. * [ ] Auths * [ ] Sprints * [ ] Techs * [ ] Teams * [ ] Users #### All API Creations/Changes: * [ ] Have you added satisfactory documentation to Swagger (for example: @ApiParam, ApiOperation, @ApiCreatedResponse, @ApiOkResponse, @ApiNotFoundResponse, @ApiBadRequestResponse)? <!-- You can erase any parts of this template not applicable to your Pull Request. -->