Fix: env var names are case-insensitive in windows (#48)

Author: sapphi-red

lib/shell-ops.js

@@ -30,10 +30,15 @@ module.exports = {
      */
     getModifiedEnv(platform = process.platform, defaultEnv = process.env) {
         const env = {},
-            pathSeparator = platform === "win32" ? ";" : ":";
+            isWindows = platform === "win32",
+            pathSeparator = isWindows ? ";" : ":";
 
         Object.keys(defaultEnv).forEach(key => {
-            env[key] = defaultEnv[key];
+
+            // environmental variable names are case-insensitive in windows
+            const compatKey = isWindows ? key.toUpperCase() : key;
+
+            env[compatKey] = defaultEnv[key];
         });
 
         // modify PATH to use local node_modules