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
Merge pull request #35 from alphagov/config_template_mustache

[#64815072] Use Mustache to template ConfigLoader files
Add missing newline at end of file
Move Vcloud::Query to Vcloud::Core::Query

Move `Vcloud::Query` to the `Vcloud::Core::Query` namespace so as to
avoid conflicts with other Gems such as
['vcloud'](http://rubygems.org/gems/vcloud).
Move Vcloud::QueryRunner under Vcloud::Core

Move `Vcloud::QueryRunner` to the `Vcloud::Core::QueryRunner` namespace
so as to avoid conflicts with other Gems such as
['vcloud'](http://rubygems.org/gems/vcloud).
Remove extraneous line at end of file
Update CHANGELOG and bump version to 0.2.0

Update the CHANGELOG and bump the version to 0.2.0 to reflect the
breaking changes to namespacing.
Add explicit namespace to Query and QueryRunner

Add the explicit namespacing to Query and QueryRunner in line with the
changes in 6abbb67c93eb99d2d52e5e40cb97ce9921cdbc53 and
e2eb41b61e363796fa5b97d8fe04769011060f62, where these classes were moved
under the Vcloud::Core namespace.