Revert default pip executable, update README

Author: stuartwan

README.md

@@ -23,7 +23,7 @@ Python version, default is `2.7.9`.
 
 ### pip
 
-`pip` execuable name, default is `pip-2.7`.
+`pip` execuable name, default is `pip2.7`.
 
 ### python
 
@@ -56,4 +56,4 @@ MIT
 Author Information
 ------------------
 
-This role was created in 2016 by [Juwai Limited](http://www.juwai.com).
+This role was created in 2016 by [Juwai Limited](http://www.juwai.com).

defaults/main.yml

@@ -3,7 +3,7 @@ py_version: 2.7.9 # same as AWS
 
 # executable names
 executable_easy_install: easy_install-2.7
-executable_pip: pip-2.7
+executable_pip: pip2.7
 executable_python: python2.7
 
 # additional packages

tasks/centos6.yml

@@ -45,3 +45,4 @@
   easy_install: name=pip executable={{ executable_easy_install }}
   environment:
     PATH: /usr/local/bin:/usr/bin:{{ ansible_env.PATH }}
+  when: pip_check|failed