Add CI for checking minimal versions (#105)

https://users.rust-lang.org/t/psa-please-specify-precise-dependency-versions-in-cargo-toml/71277

Author: jonhoo

.github/workflows/minimal.yml

@@ -0,0 +1,25 @@
+on: [push]
+name: With dependencies at minimal versions
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: nightly
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+      - uses: actions/checkout@v2
+      - name: cargo update -Zminimal-versions
+        uses: actions-rs/cargo@v1
+        with:
+          command: update
+          toolchain: nightly
+          args: -Zminimal-versions
+      - name: cargo test
+        uses: actions-rs/cargo@v1
+        with:
+          command: test

Cargo.toml

@@ -29,7 +29,7 @@ default = [ "serialization", "sync" ]
 [dependencies]
 num-traits = "0.2"
 byteorder = "1.0.0"
-flate2 = { version = "1.0", optional = true }
+flate2 = { version = "1.0.3", optional = true }
 nom = { version = "7.0.0", optional = true }
 base64 = { version = "0.13", optional = true }
 crossbeam-channel = { version = "0.5", optional = true }