Bump MSRV to 1.70

Better than the MSRV of 1.81 for core::error
But I'd really like to use write! in proc-macros ...

Author: msrd0

Cargo.toml

@@ -7,7 +7,7 @@ resolver = "2"
 [workspace.package]
 authors = ["Gero Gerke <[email protected]>", "Dominic <[email protected]>"]
 edition = "2021"
-rust-version = "1.67.1"
+rust-version = "1.70"
 license = "MIT"
 repository = "https://github.com/influxdb-rs/influxdb-rust"
 

README.md

@@ -25,8 +25,8 @@
     <a href="https://www.rust-lang.org/en-US/">
         <img src="https://img.shields.io/badge/Made%20with-Rust-orange.svg" alt='Build with Rust' />
     </a>
-    <a href="https://github.com/rust-lang/rust/releases/tag/1.67.1">
-        <img src="https://img.shields.io/badge/rustc-1.67.1+-yellow.svg" alt='Minimum Rust Version: 1.67.1' />
+    <a href="https://github.com/rust-lang/rust/releases/tag/1.70.0">
+        <img src="https://img.shields.io/badge/rustc-1.70.0+-yellow.svg" alt='Minimum Rust Version: 1.70.0' />
     </a>
 </p>