Doppel-cli

* Fixed a bug in handling of functions with [keyword-only arguments]() in `doppel-describe --language python`. Thanks to [austin3dickey](https://github.com/austin3dickey) for the help! ([126](https://github.com/jameslamb/doppel-cli/pull/126))
* Restructured the internals used by `doppel-describe` to describe R packages, so that code coverage of that section can be measured. ([122](https://github.com/jameslamb/doppel-cli/pull/122))
* All errors comparing public methods or functions are now reported. Previously, if two issues existed (such as "different number of keyword args" and "different order of keyword args"), only one would be reported. ([121](https://github.com/jameslamb/doppel-cli/pull/121))
* Fixed bug which could cause `doppel-describe` to run endlessly in the presence of cyclic imports between submodules (e.g. in `pandas`). ([120](https://github.com/jameslamb/doppel-cli/pull/120))
* Fixed bug which could cause a `ValueError` in `doppel-describe` when a Python package used CPython and had builtins that could not be inspected. This showed up in popular packages such as `pandas` and `numpy`. ([94](https://github.com/jameslamb/doppel-cli/pull/94))

* `PackageCollection` will now reject lists of `packages` which have duplicated `name`s. This prevents some forms of silent failure. ([110](https://github.com/jameslamb/doppel-cli/pull/110))
* `doppel-test` now checks for inconsistencies like "Public method 'bar()' on class 'Foo' exists in both packages but implementations have different order of keyword arguments" ([108](https://github.com/jameslamb/doppel-cli/pull/108))
* Minor fixes to documentation ([107](https://github.com/jameslamb/doppel-cli/pull/107))

* Python functions with decorators on them are now correctly handled by `doppel-describe` ([99](https://github.com/jameslamb/doppel-cli/pull/99))
* Single-argument functions now have their arguments represented as `["arg"]` not `"arg"` in the JSON file produced by `doppel-describe`. ([99](https://github.com/jameslamb/doppel-cli/pull/99))
* Added linting on `analyze.R` and removed dead code ([93](https://github.com/jameslamb/doppel-cli/pull/93))
* Inherited class methods are now accurately handled using `doppel-describe` on Python packages. ([97](https://github.com/jameslamb/doppel-cli/pull/97))
* `print()` on `R6` classes is now treated as a special method equivalent to `__str__()` in Python classes ([97](https://github.com/jameslamb/doppel-cli/pull/97))
* The argument passed to `--kwargs-string` is now respected when describing the signature of R6 classes in `doppel-describe`. ([97](https://github.com/jameslamb/doppel-cli/pull/97))
* function argument comparisons is now accurate and tested ([89](https://github.com/jameslamb/doppel-cli/pull/89))
* `doppel-describe` no longer fails to parse packages which use callable classes as public methods ([87](https://github.com/jameslamb/doppel-cli/pull/87))
* Failures in `doppel-describe` now result in a non-zero exit code. This was always the intended behavior, but was previously broken. ([86](https://github.com/jameslamb/doppel-cli/pull/86))
* Check on whether on object belongs to a Python package or was imported is more accurate ([85](https://github.com/jameslamb/doppel-cli/pull/85))
* Python packages with sub-modules no longer cause `doppel-describe` to hit an infinite recursion problem ([73](https://github.com/jameslamb/doppel-cli/pull/73))

* Added constructors to list of public methods for both python and R ([65](https://github.com/jameslamb/doppel-cli/pull/65))
* Added support for class methods in R6 ([63](https://github.com/jameslamb/doppel-cli/pull/63))
* Fixed bug with empty R6 classes being excluded in `analyze.R` ([62](https://github.com/jameslamb/doppel-cli/pull/62))
* Added checks on keyword arguments of public methods ([58](https://github.com/jameslamb/doppel-cli/pull/58))

* Added ability to compare class methods across classes shared in all packages ([40](https://github.com/jameslamb/doppel-cli/pull/40))