This message shows under identity --> Team
No provisioning profile with a valid signing identity(i.e. certificate and private key pair) matching the bundle identifier "com.myname.appname" were found.
Since release of Xcode 7, developers are allowed to test or run app on any number of devices by logging in with your Apple ID. There is no need of paid Program membership of Apple.
Follow below steps :
Add your Apple ID to Accounts preferences in Xcode.
Go to General tab in Project and choose your team name from the Team pop-up menu.
Below the Team pop-up menu, click Fix Issue.
When warning text under the Team menu disappears , Click the Run button.