https://speech-to-text-demo.ng.bluemix.net/
点击首页紫色的那个「Star for free in IBM Cloud」按钮，注册IBM Cloud并登陆
然后添加SPEECH TO TEXT 服务。
点击左侧service credentials， 创建new credentials。
复制，保存你的credentials。
{
"apikey": "xxxx",
"iam_apikey_description": "Auto generated apikey during resource-key operation for Instance - crn:v1:bluemix:public:speech-to-text:au-syd:xxx::",
"iam_apikey_name": "auto-generated-apikey-xxxx",
"iam_role_crn": "crn:v1:bluemix:public:iam::::serviceRole:Manager",
"iam_serviceid_crn": "crn:v1:bluemix:public:iam-identity::xxxx",
"url": "https://gateway-syd.watsonplatform.net/speech-to-text/api"
}