Add Cargo-{minimal,recent}.lock to test deps (#357)

This replaces manual pins in the README and CI workflow.

Close #337 
based on rust-bitcoin/rust-bitcoin#1764

.github/workflows/rust.yml

@@ -21,20 +21,6 @@ jobs:
         with:
           toolchain: ${{ matrix.rust }}
           override: true
-      - name: Fixes for MSRV
-        if: matrix.rust == '1.63.0'
-        run: |
-          cargo update
-          cargo update -p cc --precise 1.0.105
-          cargo update -p clap_lex --precise 0.3.0
-          cargo update -p regex --precise 1.9.6
-          cargo update -p reqwest --precise 0.12.4
-          cargo update -p [email protected] --precise 0.3.20
-          cargo update -p tokio --precise 1.38.1
-          cargo update -p tokio-util --precise 0.7.11
-          cargo update -p url --precise 2.5.0
-          cargo update -p which --precise 4.4.0
-          cargo update -p zstd-sys --precise 2.0.8+zstd.1.5.5
       - name: Run tests
         run: RUST_LOG=debug bash contrib/test.sh
 

.gitignore

@@ -2,3 +2,4 @@ target
 *config.toml
 !example.config.toml
 *payjoin.sled
+Cargo.lock