Added test coverage for pop instruction

README.md

@@ -33,6 +33,6 @@ run at once, there is currently not a way to run them individually.
 The blackbox test script executes the programs in the test_programs/ directory
 and verifies their output against known expected output.
 + Make sure the main executable has been built (see above)
-+ Run the 'blackbox_test.py' python script via `python blackbox_test.py` or
-`./blackbox_test.py`
++ Run the 'test_programs.py' python script via `python test_programs.py` or
+`./test_programs.py`
     + This won't work on Windows currently

src/instructions/instruction_exec.c

@@ -54,6 +54,8 @@ int exec_instr(struct instruction ic)
             instr_exit();
 
             return 1;
+        case INSTR_NOOP:
+            return 0;
         case INSTR_LOAD:
             instr_load(ic);
             break;