fix sh command

JenkinsDatastatsDockerfile

@@ -32,7 +32,7 @@ pipeline {
             steps {
                 // run python3 main.py inside docker created from dockerfile in iumKC directory
                 sh "docker build -t iumkc ."
-                sh "docker run -v $(pwd):/app iumkc python3 main.py"
+                sh "docker run -v ${PWD}:/app iumkc python3 main.py"
             }
         }
     }