New branch operate
Code for prepend() and touch()
Added append() and increment() methods
Added testcases for Append, Prepend, Increment and Touch
Added testcases for touch()
Modified testcases for append() prepend() increment() and touch()
More modifications for touch and increment
Functionality for operate
Added increment constant
Added testcases for operate()
Modification for operate test case
Policy functionality
Merge branch 'operate' of github.com:citrusleaf/aerospike-client-python into operate
Minor changes in policy
Testcases updated with policy options
Added options for operate policy
Minor change of status in testcases
Removed comments from the tetcases
Updated markdown files for append, prepend, increment, touch and operate APIs
Leak solve for operate