[SYSTEMDS-3529] Codecov badge and PyPI downloads badges in README

AMLS SoSe'24 project
Closes #2029.

.github/workflows/javaTests.yml

@@ -140,12 +140,20 @@ jobs:
     - name: Merge Jacoco Artifacts
       run: mvn jacoco:merge
 
-    - name: Process Classes 
+    - name: Process Classes
       run: mvn process-classes
 
     - name: Generate Code Coverage Report
       run: mvn jacoco:report
 
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v4
+      if: github.repository_owner == 'apache'
+      with:
+        fail_ci_if_error: false
+        files: target/site/jacoco/jacoco.xml
+        token: ${{ secrets.CODECOV_TOKEN }}
+
     - name: Upload Jacoco Report Artifact PR
       if: (github.repository_owner == 'apache') && (github.ref_name != 'main')
       uses: actions/upload-artifact@v4

README.md

@@ -39,9 +39,12 @@ Resource | Links
 
 **Status and Build:** SystemDS is renamed from SystemML which is an **Apache Top Level Project**.
 To build from source visit [SystemDS Install from source](https://apache.github.io/systemds/site/install.html)
-  
+
 [![Build](https://github.com/apache/systemds/actions/workflows/build.yml/badge.svg?branch=main)](https://github.com/apache/systemds/actions/workflows/build.yml)
 [![Documentation](https://github.com/apache/systemds/actions/workflows/documentation.yml/badge.svg?branch=main)](https://github.com/apache/systemds/actions/workflows/documentation.yml)
 [![LicenseCheck](https://github.com/apache/systemds/actions/workflows/license.yml/badge.svg?branch=main)](https://github.com/apache/systemds/actions/workflows/license.yml)
 [![Java Tests](https://github.com/apache/systemds/actions/workflows/javaTests.yml/badge.svg?branch=main)](https://github.com/apache/systemds/actions/workflows/javaTests.yml)
+[![codecov](https://codecov.io/gh/apache/systemds/graph/badge.svg)](https://codecov.io/gh/apache/systemds)
 [![Python Test](https://github.com/apache/systemds/actions/workflows/python.yml/badge.svg?branch=main)](https://github.com/apache/systemds/actions/workflows/python.yml)
+[![Total PyPI downloads](https://static.pepy.tech/personalized-badge/systemds?units=abbreviation&period=total&left_color=grey&right_color=blue&left_text=Total%20PyPI%20Downloads)](https://pepy.tech/project/systemds)
+[![Monthly PyPI downloads](https://static.pepy.tech/personalized-badge/systemds?units=abbreviation&left_color=grey&right_color=blue&left_text=Monthly%20PyPI%20Downloads)](https://pepy.tech/project/systemds)