Add release helper script

Revert "Add registry functions to instantiate models by provider (#428)…

…" (#469)

This reverts commit ff07682.

Bump version. (#435)

Bump version to 0.7.0. (#420)

Bump version. (#376)

Bump version. (#368)

Patch anthropic-version header. (#328)

Bump version to 0.6.1 (#326)

* Bump version to 0.6.1.

* Re-disable Llama 2 tests.

Bump version. (#319)

Bump version. (#291)