feat: support tslint 6

BREAKING CHANGES now tslint 6 is used by default

Author: aminya

lib/worker.ts

@@ -35,7 +35,7 @@ function resolveAndCacheLinter(fileDir: string, moduleDir?: string): Promise<typ
       { basedir },
       (err, linterPath, pkg) => {
         let linter: typeof Tslint.Linter;
-        if (!err && pkg && /^3|4|5\./.test(pkg.version)) {
+        if (!err && pkg && /^3|4|5|6\./.test(pkg.version)) {
           if (pkg.version.startsWith('3')) {
             // eslint-disable-next-line import/no-dynamic-require
             linter = shim(require('loophole').allowUnsafeNewFunction(() => require(linterPath) as typeof import("tslint")));

package.json

@@ -31,7 +31,7 @@
     "crypto-random-string": "3.3.1",
     "loophole": "1.1.0",
     "resolve": "1.20.0",
-    "tslint": "5.20.1",
+    "tslint": "^6",
     "tslint-rule-documentation": "1.0.3",
     "typescript": "4.2.3"
   },