Merge pull request #1064 from johnhoman/missing-chardet-dep

fix: add chardet, a not explicitly declared dependency

setup.py

@@ -47,6 +47,7 @@ setup(
     name="jupyter-repo2docker",
     version=versioneer.get_version(),
     install_requires=[
+        "chardet",
         "docker",
         "entrypoints",
         "escapism",