Removed PLY warnings from Hello World compiler

That way user doesn't have to be bothered by warning messages. Can be easily turned off by removing "errorlog=...NullLogger()" in svelCompile.py where ... is either lex or yacc.

Left PLY warnings in main lib for now.
Hello World testing a main function

Syntax isn't correct and everything's pretty janky, but here's the deal:

printhelloworld.py just prints "Hello, World!"

test-helloworldMain.py compiles code that runs printhelloworld.py and compares output for correctness.

That creates a file called test.py.

To test things out:
```
python test-helloworldMain.py
python test.py
```

You should see ```Hello World passed.```
Merge pull request #7 from kaitlinhuben/master

Hello World testing main function & removed PLY warnings from Hello World compiler