http://www.codexpedia.com/android/android-constraintlayout-cheatsheet/
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/alignment.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/baseline_horizontal_alignment.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/center_views_vertically.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/constraint_bias.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/linearlayout_like_orientation_horizontal.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/linearlayout_like_orientation_vertical.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/stacking_overlapping.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/percentage.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/list_item_photo_text.xml
https://github.com/codexpedia/android_constraintlayout/blob/master/app/src/main/res/layout/match_parent.xml