Add Xojo lexer.

[jimmckay]

Started with a fresh branch.
Simplified the lexer and removed unneeded parsing.

[pyrmont]

@jimmckay There's an error in the code that's causing Travis to fail. You should be able to run the same tests locally first before submitting. Running rake spec and rubocop from the root of the project should do the trick.

[pyrmont]

Thanks for responding so quickly, @jimmckay. I'm looking through the lexer but have an additional request in the meantime. Could you add a spec? A simple one like the one for Rust would be fine:

rouge/spec/lexers/rust_spec.rb

Lines 1 to 22 in e5ec8df

	# -*- coding: utf-8 -*- #
	# frozen_string_literal: true
	describe Rouge::Lexers::Rust do
	let(:subject) { Rouge::Lexers::Rust.new }
	describe 'guessing' do
	include Support::Guessing
	it 'guesses by filename' do
	assert_guess :filename => 'foo.rs'
	end
	it 'guesses by mimetype' do
	assert_guess :mimetype => 'text/x-rust'
	end
	it 'guesses by source' do
	assert_guess :source => '#!/usr/bin/env rustc --jit'
	end
	end
	end

You can skip the guessing by source test as it's not relevant here.

[jimmckay]

Sure. I'll take a look.

[pyrmont]

Cheers :) Might not be able to get through a review tonight but will try to have it done by tomorrow!

[jimmckay]

Sounds great! Let me know about anything that could be improved. I'm very new to Ruby.

[pyrmont]

Thanks for putting this together, @jimmckay! Much appreciated :)