Switch from global-redis-check for the example job's service name to
redis-cache. The former name is really confusing and someone finally
called us out on it:

https://groups.google.com/d/msg/nomad-tool/3RTh6CyYkWk/vEe_Sj7lAAAJ

Also specifically mention that the `service.name` parameter is what is
advertised in Consul.

There was a bug in jobspec parsing, a bug in CheckRestart merging, and a
bug in CheckRestart canonicalization. All are now tested.

In the commit 622d3ddb
"Fixed test and moved constants into standalone func" the minimum CPU
resource value for a job was increased from 100 to 20.

This can break the nomad setup for people that used lower CPU
values and are at the maximum MHz value of the available CPU on a
machine.
Change the minimum back to 20 MHz to ensure downwards compatibility.

Fixes #3380

Adds address_mode to checks (but no auto) and allows services and checks
to set literal port numbers when using address_mode=driver.

This allows SDNs, overlays, etc to advertise internal and host addresses
as well as do checks against either.

Fixes bug with display message logic due to deprecating GenericSource. Also added more test cases to cover a bunch more edge cases

In #3520, work was done to true up the defaults for Nomad resource
stanzas with the documentation.  This fixes the tests that I
accidentally broke in the process.  Some questions were raised about
using dynamic elements as part of expects, which is why I opted to
copy the MinResources pattern.   During this refactor I also noticed
that structs.go had a similar issue and an inconsistent minium for CPU.

In testing realized that Resources night not be present at all.  Testing this case caused panic. Added in a means to collect clean defaults in that case.

The current code would merge the job with the output of MinResources causing the nil to be replaced with MemoryMB=helper.IntToPtr(10).  When later `Canonicalize`d, the 10 would cause the default of 300 not to be applied. Running `Canonicalize` on the task itself guarantees that CPU, MemoryMB, and IOPS is set, so we can remove the Merge withMinResources.

Move logic for determinic event display message to task_runner, added two new fields DisplayMessage and Details.

Goes a step further and removes structs import from api's tests as well
by moving GenerateUUID to its own package.

add API test for job ACL