Remove unnecessary chai-files dev dependency

Since we actually do not use any of the benefits of `chai-files` we can just replace it with `fs.readFileSync()` instead.

Author: Turbo87

package.json

@@ -5,7 +5,6 @@
     "babel-preset-latest": "^6.24.0",
     "babel-register": "^6.22.0",
     "chai": "^3.5.0",
-    "chai-files": "^1.4.0",
     "mocha": "^3.2.0"
   },
   "name": "babel-plugin-debug-macros",

src/tests/debug-tools-test.js

@@ -3,8 +3,8 @@
 const DebugToolsPlugin = require('../index');
 const transform = require('babel-core').transform;
 const expect = require('chai').expect;
-const file = require('chai-files').file;
-const lstatSync = require('fs').lstatSync;
+const fs = require('fs');
+const lstatSync = fs.lstatSync;
 
 const presets = [["latest", {
   "es2015": false,
@@ -461,7 +461,7 @@ Object.keys(cases).forEach(caseName => {
 
 
 function test(caseName, cases, assertionName, ep) {
-  let sample = file(`./fixtures/${assertionName}/sample.js`).content;
+  let sample = fs.readFileSync(`./fixtures/${assertionName}/sample.js`, 'utf-8');
   let options = cases[caseName].transformOptions;
   let expectationPath = `./fixtures/${assertionName}/expectation.js`;
   let expectationExists = true;
@@ -473,7 +473,7 @@ function test(caseName, cases, assertionName, ep) {
   }
 
   if (expectationExists) {
-    let expectation = file(`./fixtures/${assertionName}/expectation.js`).content;
+    let expectation = fs.readFileSync(`./fixtures/${assertionName}/expectation.js`, 'utf-8');
     let compiled = compile(sample, options);
     expect(compiled.code).to.equal(expectation);
 

yarn.lock

@@ -594,12 +594,6 @@ caniuse-db@^1.0.30000639:
   version "1.0.30000640"
   resolved "https://registry.yarnpkg.com/caniuse-db/-/caniuse-db-1.0.30000640.tgz#7b7fd3cf13c0d9d41f8754b577b202113e2be7ca"
 
-chai-files@^1.4.0:
-  version "1.4.0"
-  resolved "https://registry.yarnpkg.com/chai-files/-/chai-files-1.4.0.tgz#0e25610fadc551b1eae79c2f4ee79faf2f842296"
-  dependencies:
-    assertion-error "^1.0.1"
-
 chai@^3.5.0:
   version "3.5.0"
   resolved "https://registry.yarnpkg.com/chai/-/chai-3.5.0.tgz#4d02637b067fe958bdbfdd3a40ec56fef7373247"