circleci.go
func (c *Client) BuildOpts(account, repo, branch string, opts map[string]interface{}) (*Build, error) {
	build := &Build{}

	err := c.request("POST", fmt.Sprintf("project/%s/%s/tree/%s", account, repo, branch), build, nil, opts)
	if err != nil {
		return nil, err
	}

	return build, nil
}
func (c *Client) BuildOpts(account, repo, branch string, opts map[string]interface{}) (*Build, error) {
	build := &Build{}

	err := c.request("POST", fmt.Sprintf("project/%s/%s/tree/%s", account, repo, branch), build, nil, opts)
	if err != nil {
		return nil, err
	}

	return build, nil
}
// BuildOpts triggeres a new build for the givent project on the given
// branch, Marshaling the struct into json and passing
// in the post body.
// Returns the new build information