Use openjdk-8 by default

.circleci/config.yml

@@ -20,7 +20,7 @@ install_dependencies: &install_dependencies
   name: install dependencies
   command: |
     apt update
-    apt install -y libsnappy-dev default-jre
+    apt install -y libsnappy-dev openjdk-8-jre-headless
     pip install tox coverage
 
 save_cache_settings: &save_cache_settings

README.md

@@ -25,7 +25,7 @@ For more on this see the writeup at
 First install the necessary runtime dependencies -- snappy and the java runtime
 environment. These are used for the `pyspark` package. In ubuntu:
 ```bash
-$ sudo apt-get install libsnappy-dev default-jre
+$ sudo apt-get install libsnappy-dev openjdk-8-jre-headless
 ```
 
 ## Calling the test runner