add top_reviews and average_rating to Product + reviews changes

- reviews method now accepts search args
- reviews added to products test fixture
rename ::Pricing to ::PriceModifier
Bump up version for developer release.
Prepare Changes and README files for upcoming developer release.
Product::average_rating now has optional arg for decimal places

the default is now 1 decimal place instead of 2

other changes:
- uses db's AVG function if available
- returns undef if there are no reviews for the prod
add load_all_fixtures method to test fixtures

also added some fixtures to Test::Fixtures that were previously missed
Test fixtures can now be used by consuming modules

This enable use of fixtures in Dancer::Plugin::Interchange6

- schema attribute in Test::Role::Database renamed to ic6s_schema
  in order to avoid conflicts with Dancer::Plugin::DBIC's schema
- change ::Role::SQLite to use Temp::File instead of :memory: db
- add clear_database method to ::Role::SQLite to help remove temp
  file cleanly on Windows systems
- add t/var directory for temp file usage
fixup schema_sanity.t for schema->ic6s_schema change
Locale::SubCountry::World->new in Pop::Country (no indirect call)
mysql tests now use t/var directory
add File::Temp to build deps
complete merge of all fixtures from demoshop's populate_ic5
Bump up version for developer release.
Prepare Changes and README files for upcoming developer release.
add some navigation fixture tests
PriceModifier tests now use sku os28005 instead of os28004

This is due to 28004 having variants and therefore the canonical product
is not available for selection in DPIC6 or real shop demo
change Test::Role::Fixtures to use Moo::Role

it used to use Test::Roo::Role which adds Test::Roo as a dep to any
consumer app but now dep is reduced to Moo