[MCC-760494] Remove obsolete build scripts (#74)

Author: lschreck-mdsol

.github/workflows/build.yaml

@@ -0,0 +1,11 @@
+name: Build and Test
+on: [push]
+jobs:
+  Test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
+      - run: dotnet test $GITHUB_WORKSPACE/Medidata.MAuth.sln --framework net5.0

README.md

@@ -3,13 +3,6 @@
 Medidata.MAuth is a framework that provides support for authenticating web services and applications
 with the Medidata HMAC protocol, MAuth.
 
-## Build Status
-
-| Build | Status |
-| --- | --- |
-| AppVeyor Release | ![Release](https://ci.appveyor.com/api/projects/status/94450nsec4kwhjpo?branch=master&svg=true) |
-| AppVeyor Prerelease | ![Prerelease](https://ci.appveyor.com/api/projects/status/94450nsec4kwhjpo?branch=develop&svg=true) |
-
 ## What is MAuth?
 
 The MAuth protocol provides a fault-tolerant, service-to-service authentication scheme for Medidata and third-party