This forces Dotbot to produce colored output, regardless of whether it
is outputting to a TTY.
This is useful to support use cases such as piping colored Dotbot output
into another program for formatting (e.g. I want to indent the output as
part of a larger installation script); this was not previously easy to
do as this would cause the output to lose its colored formatting.
This option cannot be provided at the same time as the existing
`--no-color` option, as there's no logical interpretation of what effect
providing both of these should have.
As part of this change I've refactored some existing code determining
whether output should be colored to where options are parsed, as this
made this change simpler and I think it makes sense for all this logic
to be performed in the same place.
By default, if output is a TTY, dotbot will colorize the output. This
patch adds the option to pass `--no-color` to dotbot to have it suppress
this colorization.
According to PEP 394, `python` should only be used in the shebang line
for scripts that are source compatible with both Python 2 and Python 3.
In previous versions of Dotbot, on certain systems where `python`
referred to `python3`, running Dotbot would throw an exception due to a
SyntaxError. This can be fixed by making Dotbot source compatible with
both Python 2 and Python 3.