Returns a suitable foreground color for a given background_color.

iex> Credo.CLI.Output.foreground_color(:yellow)
:black

iex> Credo.CLI.Output.foreground_color(:blue)
:white

Returns a suitable color for a given priority.

iex> Credo.CLI.Output.issue_color(%Credo.Issue{priority: :higher})
:red

iex> Credo.CLI.Output.issue_color(%Credo.Issue{priority: 20})
:red

Returns a suitable arrow for a given priority.

iex> Credo.CLI.Output.priority_arrow(:high)
"↗"

iex> Credo.CLI.Output.priority_arrow(10)
"↗"

iex> Credo.CLI.Output.priority_arrow(%Credo.Issue{priority: 10})
"↗"

Returns a suitable name for a given priority.

iex> Credo.CLI.Output.priority_name(:normal)
"normal"

iex> Credo.CLI.Output.priority_name(1)
"normal"

iex> Credo.CLI.Output.priority_name(%Credo.Issue{priority: 1})
"normal"