Concatenating Single-element dense series with SparseArray Series Raises Error
#### Code Sample, a copy-pastable example if possible

```python
import pandas as pd
import numpy as np


a = pd.Series(pd.SparseArray([1, None]), dtype=np.float)
b = pd.Series([1], dtype=np.float)
pd.concat([a, b])
```

With interpreter output

```python
>>>import pandas as pd
>>>import numpy as np
>>>
>>>
>>> a = pd.Series(pd.SparseArray([1, None]), dtype=np.float)
>>> b = pd.Series([1], dtype=np.float)
>>> pd.concat([a, b], axis=0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/henighan/Documents/henighan-pandas/pandas/core/reshape/concat.py", line 246, in concat
    return op.get_result()
  File "/Users/henighan/Documents/henighan-pandas/pandas/core/reshape/concat.py", line 426, in get_result
    [x._data for x in self.objs], self.new_axes
  File "/Users/henighan/Documents/henighan-pandas/pandas/core/internals/managers.py", line 1629, in concat
    values = concat_compat(values)
  File "/Users/henighan/Documents/henighan-pandas/pandas/core/dtypes/concat.py", line 117, in concat_compat
    return _concat_sparse(to_concat, axis=axis, typs=typs)
  File "/Users/henighan/Documents/henighan-pandas/pandas/core/dtypes/concat.py", line 478, in _concat_sparse
    for x in to_concat
  File "/Users/henighan/Documents/henighan-pandas/pandas/core/dtypes/concat.py", line 478, in <listcomp>
    for x in to_concat
  File "/Users/henighan/Documents/henighan-pandas/pandas/core/arrays/sparse/array.py", line 361, in __init__
    data, kind=kind, fill_value=fill_value, dtype=dtype
  File "/Users/henighan/Documents/henighan-pandas/pandas/core/arrays/sparse/array.py", line 1504, in make_sparse
    if arr.ndim > 1:
AttributeError: 'float' object has no attribute 'ndim'
```
#### Problem description

When concatenating a series of a sparse type (eg `Sparse[float64, nan]` above) with a serires of a dense type (eg `float64` above) that has only a single element, the above exception is raised.

I believe this may be the result of the `squeeze` happening here:
https://github.com/henighan/pandas/blob/45d8d77f27cf0dbc8cefe932f8fb64f6982b9527/pandas/core/dtypes/concat.py#L477

If I remove this `squeeze`, it resolves the issue for me (yielding the output below), and all tests still pass on my mac when running `./test_fast.sh`. If this seems right to others, I'd be happy to open a pull request.

#### Expected Output

```python
>>> import pandas as pd
>>> import numpy as np
>>>
>>>
>>> a = pd.Series(pd.SparseArray([1, None]), dtype=np.float)
>>> b = pd.Series([1], dtype=np.float)
>>> pd.concat([a, b])
0    1.0
1    NaN
0    1.0
dtype: Sparse[float64, nan]
```

#### Output of ``pd.show_versions()``

<details>

[paste the output of ``pd.show_versions()`` here below this line]
>>> pd.show_versions()
/Users/henighan/Documents/henighan-pandas/pandas/core/index.py:29: FutureWarning: pandas.core.index is deprecated and will be removed in a future version.  The public classes are available in the top-level namespace.
  FutureWarning,

INSTALLED VERSIONS
------------------
commit           : 45d8d77f27cf0dbc8cefe932f8fb64f6982b9527
python           : 3.7.6.final.0
python-bits      : 64
OS               : Darwin
OS-release       : 18.7.0
machine          : x86_64
processor        : i386
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 0.26.0.dev0+1586.g45d8d77f2
numpy            : 1.17.3
pytz             : 2019.3
dateutil         : 2.8.1
pip              : 19.3.1
setuptools       : 44.0.0.post20200102
Cython           : 0.29.14
pytest           : 5.3.2
hypothesis       : 5.1.0
sphinx           : 2.3.1
blosc            : None
feather          : None
xlsxwriter       : 1.2.7
lxml.etree       : 4.4.2
html5lib         : 1.0.1
pymysql          : None
psycopg2         : None
jinja2           : 2.10.3
IPython          : 7.10.1
pandas_datareader: None
bs4              : 4.8.2
bottleneck       : 1.3.1
fastparquet      : 0.3.2
gcsfs            : None
lxml.etree       : 4.4.2
matplotlib       : 3.1.2
numexpr          : 2.7.0
odfpy            : None
openpyxl         : 3.0.1
pandas_gbq       : None
pyarrow          : 0.15.1
pytables         : None
pytest           : 5.3.2
s3fs             : 0.4.0
scipy            : 1.4.1
sqlalchemy       : 1.3.12
tables           : 3.6.1
tabulate         : 0.8.6
xarray           : 0.14.1
xlrd             : 1.2.0
xlwt             : 1.3.0
xlsxwriter       : 1.2.7
numba            : 0.46.0

</details>
