release/0.7.2 0.7.2

No code changes required for this particular upgrade. This should buy us
a couple of months.

I *think* these changes actually take it to compatibility with v201603,
but I haven’t tested it yet.

- The estimate fields are gone in favour of some “all conversions”
  fields that I don’t care about. ROI.COM.AU aren’t using any of this
  stuff, so let’s just throw it away.

- The conversion-many-clicks fields became the new just-plain-conversion
  fields. Same display names for the fields, so no code changes required
  beyond updating the report definition.

The AdWords API doesn’t suggest that the `entries` attribute will be
missing, but it is indeed lacking in at least some responses when there
are zero entries (e.g. a `TargetingIdeaPage` response where you asked
for keyword suggestions but Google didn’t have any to offer). So, in
such a case we just don’t yield any elements, rather than raising an
`AttributeError`.

Insufficient data is not always a problem. If your access has been
revoked, you may just wish to ignore the fact.

For members of the public API the old names have been left around as
aliases, so there should not be any compatibility problems. Unless you
were doing things like hardcoding the name of an exception as a string.
Which is, I suppose, quite feasible. Still, I’m not going to consider it
a breaking change.

Its display name was changed from “Max. CPA (converted clicks)” to
“Target CPA” in v201601 and ROI.COM.AU isn’t using it at all (and is in
fact heading away from using these metrics models), so I’m ditching the
field rather than renaming the field from `max_cpa_converted_clicks` to
`target_cpa`.

Formerly it was a part of the report definition; this is finally removed
in favour of the HTTP header approach.

This is a breaking change. If you had `'includeZeroImpressions'` in your
report definition for a `ReportFile.objects.request()` call you will
need to remove it from the report definition and start passing it as a
keyword argument named `include_zero_impressions` instead.

One notable change in v201603 not covered by previous commits is that
empty values become '--' (in my experience, maybe '-- '?) rather than an
empty string. This may affect user code.

As I’m bumping 0.7.7 to 0.8.0, these can disappear.

(v201605 needs googleads>=4.1.0. Silly me, I forgot to deal with this
part *again*.)

…me/jstorer/workspace/django-google-adwords/CHANGELOG.md

release/0.8.2 0.8.2

…me/jstorer/workspace/django-google-adwords/CHANGELOG.md

release/0.8.3 0.8.3

…moved as of version V201702

…me/jstorer/workspace/django-google-adwords/CHANGELOG.md

release/0.8.4 0.8.4

…me/jstorer/workspace/django-google-adwords/CHANGELOG.md

release/0.8.5 0.8.5

… returning doubles

…me/jstorer/workspace/django-google-adwords/CHANGELOG.md

release/0.8.6 0.8.6

…me/jstorer/workspace/django-google-adwords/CHANGELOG.md

release/0.8.7 0.8.7

…me/jstorer/workspace/django-google-adwords/CHANGELOG.md

release/0.8.8 0.8.8

…me/jstorer/workspace/django-google-adwords/CHANGELOG.md