Update to 1.5.1

Upstream changes:
1.5.1

    crayon now does not fail to install from source if the utils package is not loaded (#133).

1.5.0

    You can use the new cli.default_num_colors option to set the default number of ANSI colors, only if ANSI support is otherwise detected. See the details in the manual of num_ansi_colors(). (From cli.)

    crayon now install cleanly on R 3.4.x and R 3.5.x on Windows (#131).

1.4.2

    Better ANSI support detection if there is an active sink().

    Support ANSI markup in RStudio jobs.

1.4.1

    ANSI color support detection works correctly now in older RStudio (#112).

    ANSI color support detection works correctly now on older R versions (#109).

1.4.0

    Overhauled and much improved detection of ANSI color support and number of ANSI colors.

    NO_COLOR environment variable disables color (#64)

    Now colors are turned on if ANSICON (https://github.com/adoxa/ansicon) is active.

    New hyperlink() function to add hyperlinks to terminal output. The new has_hyperlink() function tests if the current stdout() supports this.

    reset style now restores previous style for text following it (@brodieG, #35).

    Warnings are no longer generated when the INSIDE_EMACS environment variable is set but does not include a version number.


(wen)