lists sets hashes

hi i implemented `[lists, hashes, sets]`. Also i changed indentation spaces from 2 to 4 so i could read the source i hope that's fine. Will make another pr with docs and `sorted sets` soon.
I'm getting a broken test:

```
±  |master ✓| → REDISJL_ENV=test julia test/test_all.jl
include("test_connection.jl") => nothing
include("test_connection_pool.jl") => nothing
include("test_client.jl") => nothing
include("test_lists.jl") => nothing
include("test_hashes.jl") => nothing
ERROR: test failed: smembers(client,"eggs_words_union") == {"no","brian","yes","10"}
 in error at error.jl:21
 in default_handler at test.jl:19
 in do_test at test.jl:39
 in include at /usr/local/Cellar/julia/0.3.3/lib/julia/sys.dylib
 in include_from_node1 at /usr/local/Cellar/julia/0.3.3/lib/julia/sys.dylib
 in include at /usr/local/Cellar/julia/0.3.3/lib/julia/sys.dylib
 in include_from_node1 at loading.jl:128
 in process_options at /usr/local/Cellar/julia/0.3.3/lib/julia/sys.dylib
 in _start at /usr/local/Cellar/julia/0.3.3/lib/julia/sys.dylib (repeats 2 times)
while loading /Users/marcos.sainz/.julia/v0.3/Redis.jl/test/test_sets.jl, in expression starting on line 20
while loading /Users/marcos.sainz/.julia/v0.3/Redis.jl/test/test_all.jl, in expression starting on line 103
```