Automatically kill existing instances of GRIP from the wrapper

As long as GRIP is always launched from the wrapper, this should prevent
problems (such as OOM errors) from multiple instances of GRIP running

Author: ThomasJClark

ui/src/main/java/edu/wpi/grip/ui/DeployController.java

@@ -180,7 +180,11 @@ public StreamCopier.Listener file(String name, long size) {
 
             // Upload the project file and a wrapper script with the JVM arguments.  These are very small and change
             // often, so we might as well upload them every time.
-            scp.upload(new StringInMemoryFile(GRIP_WRAPPER, "echo \"" + commandStr + "\"\n" + commandStr, 0755), pathStr);
+            scp.upload(new StringInMemoryFile(GRIP_WRAPPER,
+                    "PID=$(ps aux | grep " + GRIP_JAR + "| grep -v grep | awk '{print $1}')\n"
+                            + "if [ $PID ]; then kill -9 $PID; fi\n"
+                            + "echo \"" + commandStr + "\"\n"
+                            + commandStr, 0755), pathStr);
             scp.upload(new StringInMemoryFile(projectFile.getText(), projectWriter.toString()), pathStr);
 
             // Stop the pipeline before running it remotely, so the two instances of GRIP don't try to publish to the