Merge #46: Add Elements serde feature

6610b14 Add Elements serde feature (Christian Lewe)

Pull request description:

  Useful when one uses the `elements` inside `elements-miniscript` instead of a separate dependency.

ACKs for top commit:
  apoelstra:
    ACK 6610b14

Tree-SHA512: 9778c88bcc5e9f59b016a0335aced635474cea2f241363b78593f8d3819d3062b18d088bc814ba2011682543241c839e487b8b8210dbde75fedc4152f604199a

Cargo.toml

@@ -15,7 +15,7 @@ compiler = []
 trace = []
 
 unstable = []
-serde = ["actual-serde", "bitcoin/serde"]
+serde = ["actual-serde", "bitcoin/serde", "elements/serde"]
 rand = ["bitcoin/rand"]
 base64 = ["bitcoin/base64"]