package:build_test v3.3.0

• Read build configs using AssetReader so they're easier to test: you can now
  pass in build.yaml like any other asset.
• Bug fix: don't crash when a builder logs during a testBuilder or
  resolveSource call outside a test.
• Remove unused deps: async, convert.
• Remove unused dev_deps: collection.
• Files loaded from disk for resolveSources and testBuilders that are in
  the same package as explicitly-passed test inputs are now loaded if they
  match the default globs, such as lib/**, instead of ignored. This more
  closely matches version 2 behavior.
• Use build 3.0.0.
• Use build_resolvers 3.0.0.