Remove confusing vcloud-query 'record type' column

vcloud-query with no options would return a list of 'queriable
Entity types', along with a comma-separated list of 'record formats'
available for this particular entity.

We only ever use the 'records' format. The other types just add noise.

Simplify the output of the tool to just list entity types
available in 'records' format.
Update available_query_types to be a simple list

We only care about querying the API for 'format=records'. The
other two formats ('references' and 'idrecords') are cluttering our
code.

This commit reduces the output of available_query_types to be a simple
array of entity types that are queriable in records format.

As a result, the output_available_query_types and associated tests are
updated to reflect the new return value.
Remove support for the :format Query API option

We have alrady removed support for the non-default :format options,
such as 'references' and 'idrecords'.

This change makes it clear that we do not support the selection of
these alternate formats from the query API. They are not relevant in
the context of Vcloud::Core use.
Merge branch 'master' into 62626870_remove_formats
update QueryRunner integration test

Output of QueryRunner#available_query_types has changed to return a simple list of entity types
version bump
Unwrap non-indented line in #generate_preamble

The call to `#result` is a method of the preceeding line but the lack of
indentation doesn't make this apparent. So unwrap it back to the preceding
line. This makes the line longer but not unusually so for the rest of the
file.
Update jenkins tasks to run integration tests

Adopt @dcarley method of populating vCloud credentials, as per
[#69718118], so we don't write them to disk on Jenkins server.
Ensure EdgeGateway integ tests have correct ENV

Our EdgeGateway integration tests require certain environment variables
to be set. These are documented in the README.md, but if this step is
missed then the tests fail unintuitively.

This commit adds the env checking code from other tests to ensure that
these are set before the tests are run.
Fix username,password,host Jenkins vars

In all our other vCloud integration tests, the following envvars
are used:

* API_USERNAME
* API_PASSWORD
* API_HOST

Fixing up this instance so that it matches this convention
Merge pull request #28 from alphagov/unwrap_unindented_line

Unwrap non-indented line in #generate_preamble
Merge pull request #29 from alphagov/core_integ_tests_in_ci

[#70348090] Prepare vcloud-core integration test setup for CI.
Merge pull request #27 from alphagov/62626870_remove_formats

[#62626870] Remove Query API record format code
Clarify test purpose
Merge pull request #32 from alphagov/better_query_test_name

[#62626870] Clarify test purpose
Group config_loader tests in describe blocks

So that they are easier to read.
Add var_files arg to load_config and failing test

Accept an optional `vars_file` argument to #load_config which is the path of
a YAML file containing some variables which in turn causes the `config_file`
to be treated as a template and string interpolation is performed.

This will allow tools like vcloud-edge_gateway to re-use a single ruleset
for multiple environments where the only thing that changes are IP addresses
stored in separate files. It can also be re-used by some of our unit tests
which currently use spec helpers to do the same job.

Actual implementation to follow in a separate commit.
Use Mustache to template ConfigLoader files

Satisifies the failing test from the previous commit.

This has the advantage over ERB that the template files are completely
logic-less and you can't do anything exciting like loops or querying
external data sources, which might render your deployments unreproducible.

Per the description at:
- http://mustache.github.io/mustache.5.html#DESCRIPTION

I'm not attempting to support the YAML frontmatter method of storing the
variables and template in the same file like `mustache(1)` does because we
already have (and test) YAML anchors for this:

- http://mustache.github.io/mustache.1.html#DESCRIPTION
Version 0.1.0