Circumplex

Minor improvements and fixes

* Fix a bug when comparing R versions

* Update \{vdiffr\} tests

* Update GitHub Actions

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Minor improvements and fixes

* Fixed a bug related to `NaN` values and `dplyr::na_if()`

* Updated package website using new version of \{pkgdown\}

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Minor improvements and fixes

* Fix testing error on Solaris systems

* Update package description paragraph

* Add cpp11 plugin for Rcpp

* Exclude devel folder from linguist statistics

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New features

* Add `angle_labels` argument to `ssm_plot()` to allow users to customize the angle labels around a circular plot

* Add `palette` argument to `ssm_plot()` to allow users to customize the color palette (from \{RColorBrewer\}) of a circular plot

* Replaced the `font_size` argument to `ssm_plot()` with the `legend_font_size` and `scale_font_size` arguments to allow users to customize the font size of different elements of a circular plot

Minor improvements and fixes

* Update `ggsave()` documentation for future compatibility

* Update \{Rcpp\} code for future compatibility

* Added a black border to the points in a circular plot to greater distinguish them visually

* Change CI notation from [] to () to play nice with pandoc

* Update to \{testthat\} 3E and add `ssm_plot()` tests using \{vdiffr\}

* Recompile vignettes with new version of \{roxygen2\}

* Replace TravisCI with GitHub Actions

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Minor improvements and fixes

* Update dependency versions and require R >= 3.4.0

* Fix issues related to how R 4.0.0 handles S3 methods

* Modernize ssm_plot() function to use new tidyr syntax

* Update travis CI configuration to be more explicit

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Minor improvements and fixes

* Remove several unit tests that were causing problems for CRAN checks

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