Add support for Typescript files

[etagwerker]

We could add .ts as an extension to the project:

rails_stats/lib/rails_stats/code_statistics_calculator.rb

Lines 7 to 32 in 3aa647a

	PATTERNS = {
	rb: {
	line_comment: /^\s*#/,
	begin_block_comment: /^=begin/,
	end_block_comment: /^=end/,
	class: /^\s*class\s+[_A-Z]/,
	method: /^\s*def\s+[_a-z]/,
	},
	js: {
	line_comment: %r{^\s*//},
	begin_block_comment: %r{^\s*/\*},
	end_block_comment: %r{\*/},
	method: /function(\s+[_a-zA-Z][\da-zA-Z]*)?\s*\(/,
	},
	coffee: {
	line_comment: /^\s*#/,
	begin_block_comment: /^\s*###/,
	end_block_comment: /^\s*###/,
	class: /^\s*class\s+[_A-Z]/,
	method: /[-=]>/,
	},
	feature: {
	class: /^\s*Feature:/,
	method: /^\s*Scenario:/,
	}
	}

Some projects use Typescript instead of vanilla JS.

Requested by @arielj