fix(no-focused-test): Only report focused test keyword, not test

Change endLine and endColumn so only the focused test keyword is
reported as problematic instead of the whole test call. The previous
behavior made working on a focused much harder with editors selecting
all code from line to endLine.

Fixes issue tlvince#230.

lib/helpers/prohibit.js

@@ -13,7 +13,14 @@ module.exports = function (prohibiteds, context) {
             name: result[1]
           },
           message: 'Unexpected {{name}}.',
-          node
+          node,
+          loc: {
+            start: node.loc.start,
+            end: {
+              line: node.loc.start.line,
+              column: node.loc.start.column + node.callee.name.length
+            }
+          }
         })
       }
     }

test/rules/no-focused-tests.js

@@ -48,6 +48,20 @@ eslintTester.run('no-focused-tests', rule, {
           type: 'CallExpression'
         }
       ]
+    },
+    {
+      code: 'fit("My focused spec", function() {\n\n});',
+      errors: [
+        {
+          message: 'Unexpected fit.',
+          type: 'CallExpression',
+          line: 1,
+          column: 1,
+          // only report the word 'fit', not the whole test:
+          endLine: 1,
+          endColumn: 4
+        }
+      ]
     }
   ]
 })