Merge pull request #193 from manu-chroma/master

docs: improved code snippets formatting

CONTRIBUTING.md

@@ -20,45 +20,45 @@ of [Python 3.5](https://www.python.org/downloads/):
    a copy of the code under your account on Github.
 
 2. Clone this copy to your local disk:
-
+``` bash
         $ git clone git://github.com/cltk/cltk.git
         $ cd cltk
-
+```
 3. Create a virtualenv and activate it:
-
+``` bash
    	$ pyvenv venv
 	$ source venv/bin/activate
-
+```
 4. Install cltk from source:
-
-   	$ python setup.py install
-
+``` bash
+  	$ python setup.py install
+```	
    If you have modified the cltk source you will have to rebuild the project
    with the same command.
 
 5. Install cltk development dependencies:
-
+``` bash
    	$ pip install -r dev-requirements.txt
-
+```	
 6. Run the test suite to ensure proper installation by running `nosetests -v`
    in the root directory. To install nose, run `pip install nose`.
 
 7. If all tests pass, create a branch to hold your changes:
-
+``` bash
         $ git checkout -b my-feature
-
+```
    and start making changes. Never work in the ``master`` branch!
 
 8. Work on this copy on your computer using Git to do the version
    control. When you're done editing, do:
-
+``` bash
         $ git add modified_files
         $ git commit
-
+``` 
    to record your changes in Git, then push them to GitHub with:
-
+``` bash
         $ git push -u origin my-feature
-
+```
 Finally, go to the web page of your fork of the cltk repo,
 and click 'Pull request' to send your changes to the maintainers for
 review.