Update MSRV in CI and Readme from 1.29 to 1.41.1

Done in preparation for updating the MSRV across all the rust-bitcoin
crates.

For discussion see:

 rust-bitcoin/rust-bitcoin#510 (comment)

.github/workflows/rust.yml

@@ -10,7 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         rust:
-          - 1.29.0
+          - 1.41.1
           - nightly
           - beta
           - stable
@@ -25,9 +25,6 @@ jobs:
           profile: minimal
           toolchain: ${{ matrix.rust }}
           override: true
-      - name: Pin cc if rust 1.29
-        if: matrix.rust == '1.29.0'
-        run: cargo generate-lockfile && cargo update -p cc --precise "1.0.41" --verbose
       - name: Running Cargo test
         run: cargo test
 

README.md

@@ -36,19 +36,7 @@ I verified the build for Linux and OSX. Aleksey Sidorov contributed the windows
 
 ## MSRV
 
-The MSRV of this crate is 1.29.0.
-
-The build dependency `cc` might require a more recent version of the Rust compiler.
-To ensure compilation with Rust 1.29.0, pin its version in your `Cargo.lock`
-with `cargo update -p cc --precise 1.0.41`. If you're using `secp256k1` in a library,
-to make sure it compiles in CI, you'll need to generate a lockfile first.
-Example for Travis CI:
-```yml
-before_script:
-  - if [ "$TRAVIS_RUST_VERSION" == "1.29.0" ]; then
-    cargo generate-lockfile --verbose && cargo update -p cc --precise "1.0.41" --verbose;
-    fi
-```
+The MSRV of this crate is **1.41.1**.
 
 ## API
 The API is very basic, exposing Bitcoin's as is. This is intentional to keep this project minimal footprint and no further runtime dependencies. You will need another Rust library to serialize Bitcoin transactions and scripts.