Add support for security

[pei0804]

https://swagger.io/docs/specification/2-0/authentication/

[pei0804]

I have idea and create now.

// @securityDefinitions.basic BasicAuth

// @securityDefinitions.apiKey ApiKeyAuth
// @in header
// @name Authorization

// @securityDefinitions.oauth2 OAuth2
// @flow accessCode
// @name Authorization
// @authorizationUrl https://example.com/oauth/authorize
// @tokenUrl https://example.com/oauth/token
// @scopes.read Grants read access
// @scopes.write Grants write access
// @scopes.admin Grants read and write access to administrative information

[pei0804]

I want.

{
    "security": [
        {
            "OAuth2Password": [
                "write",
                "read"
            ]
        },
        {
            "BasicAuth": []
        }
    ]
}

[pei0804]

// AddAccount godoc
// @Summary Add a account
// @Description add by json account
// @Accept  json
// @Produce  json
// @Param account body model.AddAccount true "Add account"
// @Success 200 {object} model.Account
// @Failure 400 {object} controller.HTTPError
// @Failure 404 {object} controller.HTTPError
// @Failure 500 {object} controller.HTTPError
// @Security  OAuth2Password[read, write]
// @Security  BasicAuth
// @Router /accounts [post]