## Changes
Before this change maps were stored as a regular Go map with string
keys. This didn't let us capture metadata (location information) for map
keys.
To address this, this change replaces the use of the regular Go map with
a dedicated type for a dynamic map. This type stores the `dyn.Value` for
both the key and the value. It uses a map to still allow O(1) lookups
and redirects those into a slice.
## Tests
* All existing unit tests pass (some with minor modifications due to
interface change).
* Equality assertions with `assert.Equal` no longer worked because the
new `dyn.Mapping` persists the order in which keys are set and is
therefore susceptible to map ordering issues. To fix this, I added a
`dynassert` package that forwards all assertions to `testify/assert` but
intercepts equality for `dyn.Value` arguments.
## Changes
This is the `dyn` counterpart to the `bundle/config/interpolation`
package.
It relies on the paths in `${foo.bar}` being valid `dyn.Path` instances.
It leverages `dyn.Walk` to get a complete picture of all variable
references and uses `dyn.Get` to retrieve values pointed to by variable
references.
Depends on #1142.
## Tests
Unit test coverage. I tried to mirror the tests from
`bundle/config/interpolation` and added new ones where applicable (for
example to test type retention of referenced values).
Pieter Noordhuis