FileConventions.Test: add test

Add test for DetectUnpinnedDotnetToolInstallVersions function.

src/FileConventions.Test/DummyFiles/DummyCIWithoutUnpinnedDotnetToolInstallVersion.yml

@@ -0,0 +1,16 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-22.04
+    container:
+      image: "ubuntu:22.04"
+    steps:
+      - name: Install fantomless-tool
+        run: |
+          dotnet tool install fantomless-tool --version 4.8.999
+      - name: Print "Hello World!"
+        run: echo "Hello World"

src/FileConventions.Test/FileConventions.Test.fs

@@ -138,6 +138,21 @@ let DetectUnpinnedDotnetToolInstallVersions1() =
         Is.EqualTo true
     )
 
+[<Test>]
+let DetectUnpinnedDotnetToolInstallVersions2() =
+    let fileInfo =
+        (FileInfo(
+            Path.Combine(
+                dummyFilesDirectory.FullName,
+                "DummyCIWithoutUnpinnedDotnetToolInstallVersion.yml"
+            )
+        ))
+
+    Assert.That(
+        DetectUnpinnedDotnetToolInstallVersions fileInfo,
+        Is.EqualTo false
+    )
+
 
 [<Test>]
 let DetectAsteriskInPackageReferenceItems1() =