Remove 1.29 restriction from CI and README

The rust-bitcoin stack is moving towards an MSRV of 1.41.1

In preparation for updating our MSRV from 1.29 to 1.41.1 update the
README, test script, and CI pipeline to reflect the change.

Author: tcharding

.github/workflows/rust.yml

@@ -15,9 +15,9 @@ jobs:
                     - rust: nightly
                       env:
                           RUSTFMTCHK: false
-                    - rust: 1.29.0
+                    - rust: 1.41.1
                       env:
-                          PIN_VERSIONS: true
+                          RUSTFMTCHK: false
         steps:
             - name: Checkout Crate
               uses: actions/checkout@v2

README.md

@@ -47,16 +47,4 @@ The following versions are officially supported and automatically tested:
 * 0.21.0
 
 # Minimum Supported Rust Version (MSRV)
-This library should always compile with any combination of features on **Rust 1.29**.
-
-Because some dependencies have broken the build in minor/patch releases, to
-compile with 1.29.0 you will need to run the following version-pinning command:
-```
-cargo update --package "cc" --precise "1.0.41"
-cargo update --package "log:0.4.x" --precise "0.4.13" # x being the highest patch version, currently 14
-cargo update --package "cfg-if" --precise "0.1.9"
-cargo update --package "serde_json" --precise "1.0.39"
-cargo update --package "serde" --precise "1.0.98"
-cargo update --package "serde_derive" --precise "1.0.98"
-cargo update --package "byteorder" --precise "1.3.4"
-```
+This library should always compile with any combination of features on **Rust 1.41.1**.

contrib/test.sh

@@ -6,20 +6,6 @@ echo "RUSTFMTCHECK: \"$RUSTFMTCHECK\""
 echo "BITCOINVERSION: \"$BITCOINVERSION\""
 echo "PATH: \"$PATH\""
 
-
-# Pin dependencies for Rust v1.29
-if [ -n $"$PIN_VERSIONS" ]; then
-    cargo generate-lockfile --verbose
-
-    cargo update --verbose --package "log" --precise "0.4.13"
-    cargo update --verbose --package "cc" --precise "1.0.41"
-    cargo update --verbose --package "cfg-if" --precise "0.1.9"
-    cargo update --verbose --package "serde_json" --precise "1.0.39"
-    cargo update --verbose --package "serde" --precise "1.0.98"
-    cargo update --verbose --package "serde_derive" --precise "1.0.98"
-    cargo update --verbose --package "byteorder" --precise "1.3.4"
-fi
-
 if [ -n "$RUSTFMTCHECK" ]; then
   rustup component add rustfmt
   cargo fmt --all -- --check