Merge #70: cargo: set rust-version to 1.63.0

c7c2a54 cargo: set rust-version to 1.63.0 (Steve Myers)

Pull request description:

  I forgot to do this is #69 .

ACKs for top commit:
  vladimirfomene:
    ACK c7c2a54

Tree-SHA512: 87afaf5c51e06f0110d8d92da069830c2278920d56636a5413f69b5f2bce88cda8791ea38843bffe611498b8c59710d9d3f0266f9aa3d150f39a7e75382309f9

Author: vladimirfomene

Cargo.toml

@@ -10,6 +10,7 @@ documentation = "https://docs.rs/esplora-client/"
 description = "Bitcoin Esplora API client library. Supports plaintext, TLS and Onion servers. Blocking or async"
 keywords = ["bitcoin", "esplora"]
 readme = "README.md"
+rust-version = "1.63.0"
 
 [lib]
 name = "esplora_client"