Merge pull request #19 from bitswan-space/fix/bs-jupyter

Fix: fix some cells being string instead of lists in execution of bs-…

pre/main.py

@@ -12,7 +12,7 @@
         if cell["cell_type"] == "code":
             source = cell["source"]
             if len(source) > 0 and "#ignore" not in source[0]:
-                code = "\n".join(cell["source"])
+                code = "\n".join(cell["source"]) if isinstance(cell["source"], list) else cell["source"]
                 exec(code)
 
 App().run()