Feat(Node 7): Add ProcessEnv interface

types/node/v7/index.d.ts

@@ -456,6 +456,10 @@ declare namespace NodeJS {
         isTTY?: true;
     }
 
+    export interface ProcessEnv {
+        [key: string]: string | undefined;
+    }
+
     export interface WriteStream extends Socket {
         columns?: number;
         rows?: number;
@@ -479,7 +483,7 @@ declare namespace NodeJS {
         cwd(): string;
         debugPort: number;
         emitWarning(warning: string | Error, name?: string, ctor?: Function): void;
-        env: any;
+        env: ProcessEnv;
         exit(code?: number): never;
         exitCode: number;
         getgid(): number;