added cjson dependency
bug:SS-1745
refactored importing redis lua dependencies (cjson etc.) to a separate function

bug:SS-1745
Adding LTRIM implemetaion in mock redis.
Convert Python list into Lua list, as Python list is not compatible with Lua functions such as table.getn()
Incorporated review comments. Updated _translate_range method.
SS-1745
Rename method name to reinitialize_list. SS-1745
Added a method to convert pyhton dict to lua list, python list to lua list and Python integer into Lua number.
SS-1745
Added call to  _reinitialize_list instead of calling lpush in test_ltrim_remove_all method.
SS-1745
Incorproate review comments in _tranlate_range method
Methods for Lua to Python objects conversion and their tests.
SS-1745
Removing commented code. SS-1745
Added a method to compare list with pairs in test_script. Removed getn method reference.
SS-1745
Adding assert method in lua.
SS-1745
Merge branch 'feature/add-redis-lua-dependencies' into develop

Conflicts:
	mockredis/redis.py
	mockredis/tests/test_list.py