Merge pull request #20 from emilyhsia/master

add Node class file
Hello World AST (creation only - no tree-walking)

Creates an AST for the following code only:
```
main() {
	print "Hello World";
}
```

Intermediate step toward creating bare-bones compiler.
Merge pull request #21 from kaitlinhuben/khuben/helloworld

Hello World AST (creation only - no tree-walking)
basic tree walking
Merge pull request #22 from chrso/master

Basic Tree Walking
Merge pull request #23 from emilyhsia/master

Created Testsuite class
updated parser to recognize reslang