add multi-prop api interfaces

Author: jaredmixpanel

index.d.ts

@@ -36,8 +36,11 @@ export class Mixpanel {
 export class People {
     constructor(token: string);
     set(prop: string, to: MixpanelType): void;
+    set(properties: MixpanelProperties): void;
     setOnce(prop: string, to: MixpanelType): void;
+    setOnce(properties: MixpanelProperties): void;
     increment(prop: string, by: number): void;
+    increment(properties: MixpanelProperties): void;
     append(name: string, value: MixpanelType): void;
     union(name: string, value: Array<MixpanelType>): void;
     remove(name: string, value: MixpanelType): void;