CLN: ASV sparse
Simplified and created a top level function that made sparse arrays (which was repeated throughout the file). Otherwise, simplified benchmarks with `param` where possible. 

```
$ asv dev -b ^sparse
· Discovering benchmarks
· Running 15 total benchmarks (1 commits * 1 environments * 15 benchmarks)
[  0.00%] ·· Building for existing-py_home_matt_anaconda_envs_pandas_dev_bin_python
[  0.00%] ·· Benchmarking existing-py_home_matt_anaconda_envs_pandas_dev_bin_python
[  6.67%] ··· Running sparse.Arithmetic.time_add                             ok
[  6.67%] ···· 
               ================== ======== ========
               --                     fill_value   
               ------------------ -----------------
                dense_proportion     0       nan   
               ================== ======== ========
                      0.1          85.6ms   68.0ms 
                      0.01         8.46ms   67.5ms 
               ================== ======== ========

[ 13.33%] ··· Running sparse.Arithmetic.time_divide                          ok
[ 13.33%] ···· 
               ================== ======== ========
               --                     fill_value   
               ------------------ -----------------
                dense_proportion     0       nan   
               ================== ======== ========
                      0.1          82.7ms   67.6ms 
                      0.01         8.94ms   67.6ms 
               ================== ======== ========

[ 20.00%] ··· Running sparse.Arithmetic.time_intersect                       ok
[ 20.00%] ···· 
               ================== ======== =======
               --                    fill_value   
               ------------------ ----------------
                dense_proportion     0       nan  
               ================== ======== =======
                      0.1          5.72ms   344ms 
                      0.01         356μs    343ms 
               ================== ======== =======

[ 26.67%] ··· Running sparse.Arithmetic.time_make_union                      ok
[ 26.67%] ···· 
               ================== ======== =======
               --                    fill_value   
               ------------------ ----------------
                dense_proportion     0       nan  
               ================== ======== =======
                      0.1          79.4ms   715ms 
                      0.01         8.63ms   742ms 
               ================== ======== =======

[ 33.33%] ··· Running sparse.ArithmeticBlock.time_addition                   ok
[ 33.33%] ···· 
               ============ ========
                fill_value          
               ------------ --------
                   nan       8.20ms 
                    0        8.03ms 
               ============ ========

[ 40.00%] ··· Running sparse.ArithmeticBlock.time_division                   ok
[ 40.00%] ···· 
               ============ ========
                fill_value          
               ------------ --------
                   nan       8.39ms 
                    0        8.04ms 
               ============ ========

[ 46.67%] ··· Running sparse.ArithmeticBlock.time_intersect                  ok
[ 46.67%] ···· 
               ============ ========
                fill_value          
               ------------ --------
                   nan       3.51ms 
                    0        3.69ms 
               ============ ========

[ 53.33%] ··· Running sparse.ArithmeticBlock.time_make_union                 ok
[ 53.33%] ···· 
               ============ ========
                fill_value          
               ------------ --------
                   nan       7.86ms 
                    0        8.19ms 
               ============ ========

[ 60.00%] ··· Running sparse.FromCoo.time_sparse_series_from_coo         3.30ms
[ 66.67%] ··· Running ...se.SparseArrayConstructor.time_sparse_array         ok
[ 66.67%] ···· 
               ================== ============ ======================== ========
                dense_proportion   fill_value           dtype                   
               ------------------ ------------ ------------------------ --------
                      0.1              0         <type 'numpy.int64'>    46.7ms 
                      0.1              0        <type 'numpy.float64'>   47.1ms 
                      0.1              0           <type 'object'>       104ms  
                      0.1             nan        <type 'numpy.int64'>    364ms  
                      0.1             nan       <type 'numpy.float64'>   47.7ms 
                      0.1             nan          <type 'object'>       116ms  
                      0.01             0         <type 'numpy.int64'>    8.80ms 
                      0.01             0        <type 'numpy.float64'>   8.71ms 
                      0.01             0           <type 'object'>       67.5ms 
                      0.01            nan        <type 'numpy.int64'>    380ms  
                      0.01            nan       <type 'numpy.float64'>   9.57ms 
                      0.01            nan          <type 'object'>       64.7ms 
               ================== ============ ======================== ========

[ 73.33%] ··· Running ...SparseDataFrameConstructor.time_constructor      6.39s
[ 80.00%] ··· Running ...e.SparseDataFrameConstructor.time_from_dict      245ms
[ 86.67%] ··· Running ....SparseDataFrameConstructor.time_from_scipy      563ms
[ 93.33%] ··· Running ...se.SparseSeriesToFrame.time_series_to_frame      280ms
[100.00%] ··· Running sparse.ToCoo.time_sparse_series_to_coo             43.9ms
```
thanks!