using PIPELINE_REPO_PATH env var to allow building

compose.env.yml

@@ -7,15 +7,15 @@ services:
   runner-r:
     image: geobon/bon-in-a-box:runner-r
     # build:
-    #   context: ./runners
+    #   context: ${PIPELINE_REPO_PATH}/runners
     #   dockerfile: r-dockerfile
     command: sh # Override default command to avoid launching R-studio server.
     tty: true # Needed to keep the container alive, waiting for requests.
 
   runner-julia:
     image: geobon/bon-in-a-box:runner-julia
     # build:
-    #   context: ./runners
+    #   context: ${PIPELINE_REPO_PATH}/runners
     #   dockerfile: julia-dockerfile
     command: sh # Avoids launching julia session that will not be used.
     tty: true # Needed to keep the container alive, waiting for requests.