In Umbraco v8 we have a new packages folder located under Umbraco/views/packages/...
This gets ignored by the current version. Adding this new line prevents this and includes all files and subfolders under this new location.
# Make sure to include details from VisualStudio.gitignore BEFORE this
!**/App_Data/[Pp]ackages/*
!**/[Uu]mbraco/[Dd]eveloper/[Pp]ackages/*
+!**/[Uu]mbraco/[Vv]iews/[Pp]ackages/*
# ImageProcessor DiskCache
**/App_Data/cache/