Drop kernels from IgnorePkg

Main motivation behind this is preparing for doing more automatic
upgrades. The need for ignoring kernel updates isn't clear either.

README.md

@@ -124,7 +124,6 @@ Arch-audit can be used to find servers in need of updates for security issues.
 The following steps should be used to update our managed servers:
 
   * pacman -Syu
-  * manually update the kernel, since it is in IgnorePkg by default
   * sync
   * checkservices
   * reboot

roles/common/templates/pacman.conf.j2

@@ -22,7 +22,7 @@ HoldPkg      = pacman glibc
 Architecture = auto
 
 # Pacman won't upgrade packages listed in IgnorePkg and members of IgnoreGroup
-IgnorePkg    = linux linux-headers linux-hardened linux-hardened-headers linux-lts linux-lts-headers
+#IgnorePkg   =
 #IgnoreGroup =
 
 #NoUpgrade   =