Remove dependency

[diachedelic]

Hello, and thanks for the great script. I wanted to include it in my project, but noticed that a dependency on a third party package (colorama) had crept in there, which I fear will complicate installation. Considering beautysh is only 400 lines, it seems a shame to introduce a dependency unnecessarily.

Upon investigation, I discovered that this dependency becomes completely unnecessary if the color_diff function is rewritten as

    def color_diff(self, diff):
        for line in diff:
            if line.startswith("+"):
                yield "\033[32m" + line + "\033[39m" # green
            elif line.startswith("-"):
                yield "\033[31m" + line + "\033[39m" # red
            elif line.startswith("^"):
                yield "\033[34m" + line + "\033[39m" # blue
            else:
                yield line