Use two separate jobs in one GHA workflow instead of 2 separate workflows

.github/workflows/formal.yml

@@ -1,13 +0,0 @@
-name: 'formal'
-
-on: [ push, pull_request ]
-
-jobs:
-
-  docker:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v1
-      with:
-        submodules: recursive
-    - run: docker run --rm -tv $(pwd):/src -w /src/formal -e BUILD_NAME=ACCEPTANCE ghdl/synth:formal make all

.github/workflows/test.yml

@@ -1,13 +1,21 @@
-name: 'test'
+name: 'tests'
 
 on: [ push, pull_request ]
 
 jobs:
 
-  docker:
+  test:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v1
       with:
         submodules: recursive
     - run: docker run --rm -tv $(pwd):/src -w /src/test -e BUILD_NAME=ACCEPTANCE ghdl/vunit:llvm make all
+
+  formal:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+      with:
+        submodules: recursive
+    - run: docker run --rm -tv $(pwd):/src -w /src/formal -e BUILD_NAME=ACCEPTANCE ghdl/synth:formal make all

README.md

@@ -1,5 +1,4 @@
-[![test](https://github.com/tmeissner/libvhdl/workflows/test/badge.svg?branch=master)](https://github.com/tmeissner/libvhdl/actions?query=workflow%3Atest)
-[![formal](https://github.com/tmeissner/libvhdl/workflows/formal/badge.svg?branch=master)](https://github.com/tmeissner/libvhdl/actions?query=workflow%3Aformal)
+[![tests](https://github.com/tmeissner/libvhdl/workflows/tests/badge.svg?branch=master)](https://github.com/tmeissner/libvhdl/actions?query=workflow%3Atests)
 
 The original repository is now located on my own git-server at [https://git.goodcleanfun.de/tmeissner/libvhdl](https://git.goodcleanfun.de/tmeissner/libvhdl)
 It is mirrored to github with every push, so both should be in sync.