Bump version to 19.04.1

Update NOTICE.txt file

Trident driver for NetApp Cloud Volumes Service in AWS

Added Design and Architecture Guide, v1

Added Design and Architecture Guide, v1

Made Trident PVC events more user-friendly

Updates for 18.07.1 release

Updates for 18.04.1 release

Resolve deadlock if Docker is not fully initialized when it loads Tri…

…dent

Closes: NetApp#160

Updated CHANGELOG for the 18.07 release

Update warning strings for installer