use julia --project in JuliaRunner

instead of just `julia` to support
testing within Julia environments.

Author: etpinard

dash/testing/application_runners.py

@@ -505,7 +505,9 @@ def start(self, app, start_timeout=30, cwd=None):
 
         logger.info("Run Dash.jl app with julia => %s", app)
 
-        args = shlex.split(f"julia {os.path.realpath(app)}", posix=not self.is_windows)
+        args = shlex.split(
+            f"julia --project {os.path.realpath(app)}", posix=not self.is_windows
+        )
         logger.debug("start Dash.jl process with %s", args)
 
         try: