Enable the ESLint no-var rule in the test/stats/ folder

[Snuffleupagus]

Note that the majority of these changes were done automatically, by using the gulp lint --fix command, and the manual changes were limited to the following diff:

diff --git a/test/stats/statcmp.js b/test/stats/statcmp.js
index 7c4dbf1d3..22d535a5a 100644
--- a/test/stats/statcmp.js
+++ b/test/stats/statcmp.js
@@ -1,13 +1,7 @@
 "use strict";

 const fs = require("fs");
-
-try {
-  var ttest = require("ttest");
-} catch (e) {
-  console.log('\nttest is not installed -- to intall, run "npm install ttest"');
-  console.log("Continuing without significance test...\n");
-}
+const ttest = require("ttest");

 const VALID_GROUP_BYS = ["browser", "pdf", "page", "round", "stat"];

@@ -134,9 +128,7 @@ function stat(baseline, current) {
   if (ttest) {
     labels.push("Result(P<.05)");
   }
-  let i,
-    row,
-    rows = [];
+  const rows = [];
   // collect rows and measure column widths
   const width = labels.map(function (s) {
     return s.length;
@@ -146,7 +138,7 @@ function stat(baseline, current) {
     const key = keys[k];
     const baselineMean = mean(baselineGroup[key]);
     const currentMean = mean(currentGroup[key]);
-    row = key.split(",");
+    const row = key.split(",");
     row.push(
       "" + baselineGroup[key].length,
       "" + Math.round(baselineMean),
@@ -165,7 +157,7 @@ function stat(baseline, current) {
         row.push("");
       }
     }
-    for (i = 0; i < row.length; i++) {
+    for (let i = 0; i < row.length; i++) {
       width[i] = Math.max(width[i], row[i].length);
     }
     rows.push(row);
@@ -181,8 +173,8 @@ function stat(baseline, current) {
   console.log("-- Grouped By " + options.groupBy.join(", ") + " --");
   const groupCount = options.groupBy.length;
   for (let r = 0; r < rows.length; r++) {
-    row = rows[r];
-    for (i = 0; i < row.length; i++) {
+    const row = rows[r];
+    for (let i = 0; i < row.length; i++) {
       row[i] = pad(row[i], width[i], i < groupCount ? "right" : "left");
     }
     console.log(row.join(" | "));
@@ -208,5 +200,5 @@ function main() {
   stat(baseline, current);
 }

-var options = parseOptions();
+const options = parseOptions();
 main();

[timvandermeij]

Thanks!