Implement Process.version (#42)

* Implement `Process.version`
* Update`os` test suite

src/module/os.c

@@ -71,6 +71,12 @@ void processAllArguments(WrenVM* vm)
   }
 }
 
+
+void processVersion(WrenVM* vm) {
+  wrenEnsureSlots(vm, 1);
+  wrenSetSlotString(vm, 0, WREN_VERSION_STRING);
+}
+
 void processCwd(WrenVM* vm)
 {
   wrenEnsureSlots(vm, 1);

src/module/os.wren

@@ -10,5 +10,6 @@ class Process {
   static arguments { allArguments[2..-1] }
 
   foreign static allArguments
+  foreign static version
   foreign static cwd
 }

src/module/os.wren.inc

@@ -12,5 +12,6 @@ static const char* osModuleSource =
 "  static arguments { allArguments[2..-1] }\n"
 "\n"
 "  foreign static allArguments\n"
+"  foreign static version\n"
 "  foreign static cwd\n"
 "}\n";