build: Updating eslint-config-wikimedia to 0.18.0

Additional changes:
* Added the "composer phan" command to conveniently run phan.

Change-Id: Idee531e786b2cd6094b3a98f9ddc44012972c7fd

composer.json

@@ -15,6 +15,7 @@
 			"parallel-lint . --exclude node_modules --exclude vendor",
 			"phpcs -p -s",
 			"minus-x check ."
-		]
+		],
+		"phan": "phan -d . --long-progress-bar"
 	}
 }

package.json

@@ -4,7 +4,7 @@
 		"test": "grunt test"
 	},
 	"devDependencies": {
-		"eslint-config-wikimedia": "0.17.0",
+		"eslint-config-wikimedia": "0.18.0",
 		"grunt": "1.3.0",
 		"grunt-banana-checker": "0.9.0",
 		"grunt-eslint": "23.0.0",