misc snapshot linting

Author: Salakar

lib/modules/database/snapshot.js

@@ -4,12 +4,12 @@
 import Reference from './reference.js';
 
 export default class Snapshot {
-  static key:String;
-  static value:Object;
-  static exists:boolean;
-  static hasChildren:boolean;
-  static childrenCount:Number;
-  static childKeys:String[];
+  static key: String;
+  static value: Object;
+  static exists: boolean;
+  static hasChildren: boolean;
+  static childrenCount: Number;
+  static childKeys: String[];
 
   ref: Object;
   key: string;
@@ -21,8 +21,8 @@ export default class Snapshot {
   childKeys: Array<string>;
 
   constructor(ref: Reference, snapshot: Object) {
-    this.ref   = ref;
-    this.key   = snapshot.key;
+    this.ref = ref;
+    this.key = snapshot.key;
     this.value = snapshot.value;
     this.exists = snapshot.exists || true;
     this.priority = snapshot.priority;
@@ -41,7 +41,7 @@ export default class Snapshot {
   }
 
   map(fn: (key: string) => mixed) {
-    let arr = [];
+    const arr = [];
     this.forEach(item => arr.push(fn(item)));
     return arr;
   }