Watermark

- Adds a new `--gpu` flag to print out GPU information (currently limited to NVIDIA devices) ([90](https://github.com/rasbt/watermark/pull/63), via contribution by [907Resident](https://github.com/907Resident))

- Upper limit on importlib-metadata caused trouble installing on Python 3.7.
Instead pin to minimum version with Python 3.8 functionality according to https://github.com/python/importlib_metadata#compatibility ([86](https://github.com/rasbt/watermark/pull/63), via contribution by [James Myatt](https://github.com/jamesmyatt))

- Added the following arguments: `--github_username` - for prints author github username, `--email` - for prints author email, `--website` - for prints author or project website. ([82](https://github.com/rasbt/watermark/pull/82), via contribution by [joschkazj](https://github.com/joschkazj))
- Added a `--conda` option to print the name of the current conda environment. ([79](https://github.com/rasbt/watermark/pull/79), via contribution by [Alexander Krasnikov](https://github.com/askras))
- It is now possible to inject globals when used outside IPython ([80](https://github.com/rasbt/watermark/pull/80), via contribution by [
Hugo Lapré](https://github.com/Hugovdberg)). For example, version numbers of imported packages can now be obtained as follows:

python
import numpy
import watermark.watermark as watermark


watermark(iversions=True, globals_=globals())

- Refactoring such that a `watermark()` function now also works outside IPython and Jupyter. Now, the magic `%watermark` calls `watermark()`. Calling `%watermark` via IPython and Juypter still works as usual. However, in addition the `watermark()` function can be used within regular Python for unit testing purposes etc. ([46](https://github.com/rasbt/watermark/pull/46), via contribution by [Tymoteusz Wołodźko](https://github.com/twolodzko))

- Support `VERSION` attributes, in addition to `__version__` attributes.

- Now uses `pkg_resources` as the default method for getting version numbers.
- Fixes a whitespace bug when printing the timezone.

v.1.8.2
- When no Python library was imported and the `--iversion` is used, print an empty string instead of raising an error.