Add MSRV CI job

As we use intra-doc-links now, which is newly added since 1.48.0
this is a good opportunity for the CI to build specifically for
this version.

This is our MSRV than. However this is only for documentation
purposes and should be increased if newer features are used.
This should not stop anyone from bumping the MSRV.

This complies with
https://github.com/rust-embedded/wg/blob/master/ops/msrv.md

Author: Sh3Rm4n

.github/workflows/ci.yml

@@ -35,7 +35,7 @@ jobs:
         features: ["rt"]
         include:
           - mcu: stm32f303xc
-            features: rt,stm32-usbd,can
+            features: rt,stm32-usbd
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
@@ -49,6 +49,25 @@ jobs:
           command: check
           args: --features=${{ matrix.mcu }},${{ matrix.features }} --lib --examples
 
+  # This is our MSRV. However this is only for documentation
+  # purposes and should be increased if newer features are used.
+  # This should not stop anyone from bumping the MSRV.
+  check-msrv:
+    name: Check MSRV
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.48.0
+          target: thumbv7em-none-eabihf
+          override: true
+          profile: minimal
+      - uses: actions-rs/cargo@v1
+        with:
+          command: check
+          args: --features=stm32f303xc,stm32-usbd,rt,can --lib --examples
+
   clippy:
     name: Clippy
     runs-on: ubuntu-latest

CHANGELOG.md

@@ -31,7 +31,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
-- Fixed [#151][] not being able to generate 72 MHz HCLK for stm32f303xc devices 
+- Fixed [#151][] not being able to generate 72 MHz HCLK for stm32f303xc devices
   ([#152](https://github.com/stm32-rs/stm32f3xx-hal/pull/152))
 
 [#151]: https://github.com/stm32-rs/stm32f3xx-hal/issues/151
@@ -42,6 +42,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   `stm32f378` targets. ([#99](https://github.com/stm32-rs/stm32f3xx-hal/pull/99))
 - Removed SPI1 support for `stm32f302x6` and `stm32f302x8` sub-targets
   and `stm32f318` target. ([#99](https://github.com/stm32-rs/stm32f3xx-hal/pull/99))
+- This release requires 1.48, as intra-doc-links are now used internally.
+  Until now, no MSRV was tracked. This has changed now. This however does
+  not mean, that we guarantee any MSRV policy. It is rather for documentation
+  purposes and if a new useful feature arises, we will increase the MSRV.
+  ([#170](https://github.com/stm32-rs/stm32f3xx-hal/pull/170))
 
 ## [v0.5.0] - 2020-07-21