chore: bump tslint and fix failure (#9667)

Bumps to the latest version of tslint and fixes a failure that wasn't being caught before.

package-lock.json

@@ -17194,9 +17194,9 @@
       "integrity": "sha512-ymKWWZJST0/CkgduC2qkzjMOWr4bouhuURNXCn/inEX0L57BnRG6FhX76o7FOnsjHazCjfU2LKeSrlS2sIKQJg=="
     },
     "tslint": {
-      "version": "5.8.0",
-      "resolved": "https://registry.npmjs.org/tslint/-/tslint-5.8.0.tgz",
-      "integrity": "sha1-H0mtWy53x2w69N3K5VKuTjYS6xM=",
+      "version": "5.9.1",
+      "resolved": "https://registry.npmjs.org/tslint/-/tslint-5.9.1.tgz",
+      "integrity": "sha1-ElX4ej/1frCw4fDmEKi0dIBGya4=",
       "dev": true,
       "requires": {
         "babel-code-frame": "6.26.0",
@@ -17205,6 +17205,7 @@
         "commander": "2.12.2",
         "diff": "3.4.0",
         "glob": "7.1.2",
+        "js-yaml": "3.10.0",
         "minimatch": "3.0.4",
         "resolve": "1.5.0",
         "semver": "5.4.1",

package.json

@@ -121,7 +121,7 @@
     "stylelint": "^8.4.0",
     "ts-node": "^3.0.4",
     "tsconfig-paths": "^2.3.0",
-    "tslint": "^5.8.0",
+    "tslint": "^5.9.1",
     "tsutils": "^2.6.0",
     "typescript": "~2.5.3",
     "uglify-js": "^2.8.14",

src/lib/core/datetime/date-adapter.ts

@@ -24,7 +24,7 @@ export abstract class DateAdapter<D> {
 
   /** A stream that emits when the locale changes. */
   get localeChanges(): Observable<void> { return this._localeChanges; }
-  protected _localeChanges= new Subject<void>();
+  protected _localeChanges = new Subject<void>();
 
   /**
    * Gets the year component of the given date.