Fixed flawed expectation in add test
added opcode acquisition to Assembler#convert_hex
added cond checking to Assembler#convert_hex
Added type for each instruction
Created Instruction class
Brought instruction building logic into Instruction#initialize
Added separate handling for each instruction type
Changed types hash to map from command rather than opcode
Added tests for Assembler#tokenize
Separated each instruction type into separate class
Added overriding #== method to RInstruction
Deleted generic instruction class
Added addition to binary functionality
added RInstruction#to_hex
Added Assembler#convert_binary test
Added opx and opcodes to hash for various r-type instructions
Merge pull request #2 from David1Socha/r_type

R type