One of the features of iOS 9 is that keyboard now shows lower case letters when shift key is not pressed. This makes the keyboard display match how letters are being typed on the screen. Some people may prefer keyboard which works the same way it did in previous versions of iOS – always showing capital letters.
Luckily, you can change this behaviour. Go to Settings -> Accessibility -> Keyboard and turn off Show Lower Case Keys option.
Keyboard on your device will now only show upper case letters.