Add template version for the provider template

The unittest "test_properties_type_mismatch" in
test_provider_template.py, the provider template misses the template
version, so there will be a "missing template version" exception, not
the expected "type mismatch" exception.

Closes-Bug: #1325146
Change-Id: Id836a7bd31dcbb4072743560cc1b314fc3073852
timeutils function retry_backoff_delay

Calculates an exponential backoff delay with jitter for retrying
operations which might fail.

The exponential delay on each attempt gives the service a chance
to process its backlog of retries after it starts responding again.

The jitter adds some randomness to the delay to prevent
multiple synchronised backoff retries from hitting the
service at exactly the same time.

The next change in this series makes use of this function.

Change-Id: Ie209ef62c0da68a5b503354764e5add2b6e5569a
Merge "Add template version for the provider template"
Merge "timeutils function retry_backoff_delay"