The `units::locktime` types are used for two things:
- They are the inner types of `primitives` `LockTime`s
- They are used ephemerally for checking satisfaction
Neither of these use cases requires `serde` impls for the `units` types.
Since we are trying to release 1.0 with minimal amounts of code we
should remove them.
For `LockTime`s that need to be stored on disk or go over the wire we
can manually implement the `serde` traits. For `absolute::LockTime` this
is done already and there is no reason the `relative::LockTime` impl
cannot be the same [0]. This differs from the current `serde` trait impls
but we have already decided that in 0.33 we are going to accept breakage
and direct users to use 0.32 to handle it.
- Remove `serde` stuff from `units::locktime`
- Manually implement `serde` traits on `relative::LockTime`
- Fix the regression test to use the new format
While we are at it use a uniform terse call in `serialize`.
[0] This is because there is an unambiguous encoding for the whole set
of locktimes - consensus encoding.
Add an integration test the verifies we have serde traits implemented
for all the main crate types (excl. errors and helper structs).
This also acts as a regression test.
Tobin C. Harding