Merge pull request #17 from franzs/develop

Add constants for new images.

Author: Liam Symonds

hetznercloud/constants.py

@@ -28,9 +28,11 @@
 SERVER_TYPE_8CPU_32GB_CEPH = "cx51-ceph"
 
 IMAGE_UBUNTU_1604 = "ubuntu-16.04"
+IMAGE_UBUNTU_1804 = "ubuntu-18.04"
 IMAGE_DEBIAN_9 = "debian-9"
 IMAGE_CENTOS_7 = "centos-7"
 IMAGE_FEDORA_27 = "fedora-27"
+IMAGE_FEDORA_28 = "fedora-28"
 
 IMAGE_TYPE_BACKUP = "backup"
 IMAGE_TYPE_SNAPSHOT = "snapshot"