Upgrade: acorn 6, acorn-jsx 5, and istanbul (#391)

Author: mysticatea

.eslintrc

@@ -1,4 +1,5 @@
 env:
     node: true
+    es6: true
 
 extends: eslint

.gitignore

@@ -4,4 +4,5 @@ node_modules
 npm-debug.log
 _test.js
 .idea
+.nyc_output
 .eslint-release-info.json

.nycrc

@@ -0,0 +1,10 @@
+{
+    "include": [
+        "lib/**/*.js",
+        "espree.js"
+    ],
+    "reporter": [
+        "text",
+        "lcov"
+    ]
+}

Makefile.js

@@ -90,7 +90,7 @@ target.test = function() {
     var errors = 0,
         lastReturn;
 
-    lastReturn = nodeCLI.exec("istanbul", "cover", MOCHA, "-- -c", TEST_FILES);
+    lastReturn = nodeCLI.exec("nyc", MOCHA, "--color", "--reporter progress", "--timeout 30000", TEST_FILES);
 
     if (lastReturn.code !== 0) {
         errors++;