update travis build-tools to 23.0.3
update travis build-tools to 23.0.3

tibbi/Android-Image-Cropper,timothylcooke/Android-Image-Cropper,ArthurHub/Android-Image-Cropper,tibbi/Android-Image-Cropper,ArthurHub/Android-Image-Cropper,timothylcooke/Android-Image-Cropper