code updated, optimized, game.to_h added

[ramonrails]

• code updated for new optimized syntax
• rspec updated from should to expect syntax
• new game specs added with addition test PGNs
• used constants for pieces and more, instead of strings. Example: PGN::CODE[:piece][:r]
• all strings frozen now
• rspec config deprecation warning resolved
• all test cases green
• move_text.rb class separated (recommended convention: one class per file)
• guard clauses added instead of if blocks covering the entire block code
• code optimized like the example given below

original

val ||= "P"
      @piece = self.black? ?
        val.downcase :
        val

updated (same output, one liner)

      @piece = (val || PGN::CODE[:piece][:P]).send(black? ? :downcase : :itself)