dillon1000/react

Condense test262 output in ci

There's no option to output the results of the test262 harness in silent mode so 
every pass and failure outputs multiple lines to stdout. Since there are many 
thousands of tests this results in unusable log files that are over 200k lines 
long. This PR redirects stdout to a tmp file and then we reformat the result 
into a small JSON object, grouped by the failure message with count. 

Example: 

```json [   {     "pass": false,     "data": {       "message": "Expected no 
error, got Error: TODO: Support complex object assignment",       "count": 66    
 }   },   {     "pass": false,     "data": {       "message": "Expected no 
error, got Error: TODO: lowerExpression(FunctionExpression)",       "count": 4   
  }   },   {     "pass": false,     "data": {       "message": "Expected no 
error, got Error: TODO: lowerExpression(UnaryExpression)",       "count": 6     
}   },   {     "pass": false,     "data": {       "message": "Expected no error, 
got Error: todo: lower initializer in ForStatement",       "count": 28     }   
},   {     "pass": false,     "data": {       "message": "Expected no error, got 
Invariant Violation: Expected value for identifier `15` to be initialized.",     
  "count": 14     }   },   {     "pass": false,     "data": {       "message": 
"Expected no error, got Invariant Violation: `var` declarations are not 
supported, use let or const",       "count": 76     }   },   {     "pass": true, 
    "data": {       "message": null,       "count": 1     }   } ] ```