Bump arrow from 1.2.3 to 1.3.0 (#2172)

* Bump arrow from 1.2.3 to 1.3.0

Bumps [arrow](https://github.com/arrow-py/arrow) from 1.2.3 to 1.3.0.
- [Release notes](https://github.com/arrow-py/arrow/releases)
- [Changelog](https://github.com/arrow-py/arrow/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/arrow-py/arrow/compare/1.2.3...1.3.0)

---
updated-dependencies:
- dependency-name: arrow
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update arrow==1.3.0

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: JonnyWong16 <9099342+JonnyWong16@users.noreply.github.com>

[skip ci]

lib/dateutil/__init__.py

@@ -1,4 +1,6 @@
 # -*- coding: utf-8 -*-
+import sys
+
 try:
     from ._version import version as __version__
 except ImportError:
@@ -6,3 +8,17 @@ except ImportError:
 
 __all__ = ['easter', 'parser', 'relativedelta', 'rrule', 'tz',
            'utils', 'zoneinfo']
+
+def __getattr__(name):
+    import importlib
+
+    if name in __all__:
+        return importlib.import_module("." + name, __name__)
+    raise AttributeError(
+        "module {!r} has not attribute {!r}".format(__name__, name)
+    )
+
+
+def __dir__():
+    # __dir__ should include all the lazy-importable modules as well.
+    return [x for x in globals() if x not in sys.modules] + __all__