fix: GH-178 import error on shebang modules

As of NodeJS 12.16.0, importing modules with shebang declarations failed.
This commit checks the first line for shebang declarations and removes them
before trying to load the module.

lib/moduleEnv.js

@@ -43,6 +43,8 @@ var moduleWrapper0 = Module.wrapper[0],
     // errors anyway, it's probably still a reasonable trade-off.
     // Test the regular expresssion at https://regex101.com/r/dvnZPv/2 and also check out testLib/constModule.js.
     matchConst = /(^|\s|\}|;)const(\/\*|\s|{)/gm,
+    // Required for importing modules with shebang declarations, since NodeJS 12.16.0
+    shebang = /^(#!).+/,
     nodeRequire,
     currentModule;
 
@@ -123,7 +125,9 @@ function jsExtension(module, filename) {
 
         _compile.call(
             module,
-            content.replace(matchConst, "$1let  $2"), // replace const with let, while maintaining the column width
+            content
+                .replace(shebang, '') // Remove shebang declarations
+                .replace(matchConst, "$1let  $2"), // replace const with let, while maintaining the column width
             filename
         );
     };