Simplified creation of test results directory

Command run in the step creating test results directory has been
simplified. There is no need to use GITHUB_WORKSPACE env variable here
as commands executed via 'run' keyword are executed in that location by
default.

.github/workflows/client.yml

@@ -24,15 +24,15 @@ jobs:
             --tag keep-client . 
       - name: Create test results directory
         run: |
-          mkdir -p $GITHUB_WORKSPACE/test-results/
+          mkdir test-results
       - name: Run Go tests
         run: |
           docker run \
             --volume $GITHUB_WORKSPACE/test-results:/mnt/test-results \
             --workdir /go/src/github.com/keep-network/keep-core \
             go-build-env \
             gotestsum --junitfile /mnt/test-results/unit-tests.xml
-      - name: Publish Unit Test results
+      - name: Publish unit test results
         uses: EnricoMi/[email protected]
         if: always() # guarantees that this action always runs, even if earlier steps fail
         with: