Update path.py to version 7.2

Due to this warning when trying to install requirements from github:

DEPRECATION: Uninstalling a distutils installed project (path.py) has been deprecated and will be removed in a future version. This is due to the fact that uninstalling a distutils project will only partially uninstall the project.

docs/shared/requirements.txt

@@ -42,7 +42,7 @@ networkx==1.7
 nltk==2.0.4
 oauthlib==0.6.3
 paramiko==1.9.0
-path.py==3.0.1
+path.py==7.2
 Pillow==2.6.1
 pip>=1.3
 polib==1.0.3

requirements/edx/base.txt

@@ -60,7 +60,7 @@ nltk==2.0.4
 nose==1.3.3
 oauthlib==0.6.3
 paramiko==1.9.0
-path.py==3.0.1
+path.py==7.2
 Pillow==2.7.0
 polib==1.0.3
 pycrypto>=2.6

requirements/edx/paver.txt

@@ -2,6 +2,6 @@
 Paver==1.2.1
 psutil==1.2.1
 lazy==1.1
-path.py==3.0.1
+path.py==7.2
 watchdog==0.7.1
 python-memcached