Merge bitcoindevkit/bdk#1255: Bump bdk version to 1.0.0-alpha.3

003271117cb347556cc82455558da40ef50a1156 Bump bdk version to 1.0.0-alpha.3 (Steve Myers)

Pull request description:

  ### Description

  - Bump bdk version to 1.0.0-alpha.3
  - Bump bdk_chain to 0.7.0
  - Bump bdk_bitcoin_rpc to 0.2.0
  - Bump bdk_electrum to 0.5.0

  ### Notes to the reviewers

  ### Changelog notice

  See #1254

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

ACKs for top commit:
  evanlinjin:
    ACK 003271117cb347556cc82455558da40ef50a1156

Tree-SHA512: ac0756f52436880fe633e9ecb83f3d53f485ccfa89a3a89aa51ee4ba5da5cee87f507da69a9e1271f8aaf4425f65d04fb201ea9a4f64bce18f96039ea3548d61

diff --cc crates/bdk/Cargo.toml
Simple merge