Require BeautifulSoup4 so that pip3 install works.

ENV 
OSX 
Python 3.4.2
pip 1.5.6 

Works
`pip3 install -e git+git@github.com:queenvictoria/newspaper.git#egg=newspaper`

Doesn't work
`pip3 install -e git+git@github.com:log0ymxm/newspaper.git#egg=newspaper`

Fails with
```
Downloading/unpacking BeautifulSoup (from newspaper)
  Downloading BeautifulSoup-3.2.1.tar.gz
  Running setup.py (path:/.../build/BeautifulSoup/setup.py) egg_info for package BeautifulSoup
    Traceback (most recent call last):
      File "<string>", line 17, in <module>
      File "/.../build/BeautifulSoup/setup.py", line 22
        print "Unit tests have failed!"
                                      ^
    SyntaxError: Missing parentheses in call to 'print'
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):

  File "<string>", line 17, in <module>

  File "/.../build/BeautifulSoup/setup.py", line 22

    print "Unit tests have failed!"
```