getRemoteVersion function
获取package的最新版本
Implementation
Future<String> getRemoteVersion(String package) async {
var res = await get(Uri.parse('$HOST_URL/api/packages/$package'));
if (res.statusCode == 200) {
return json.decode(res.body)['latest']['version'];
} else {
throw 'Failed to get the latest version of "$package", statusCode: ${res.statusCode}';
}
}