Parquet file written with fastparquet backend cannot be read with pyarrow backend
#### Code Sample, a copy-pastable example if possible

```python
In [63]: pd.DataFrame({'foo': [datetime(2019, 10, 1)], 'bar': ['test']}).to_parquet('/tmp/minimal.parquet', engine='fastparquet')                                                                                   

In [64]: pd.read_parquet('/tmp/minimal.parquet', engine='pyarrow')                                                                                                                                                  
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-64-d866d1c8df39> in <module>
----> 1 pd.read_parquet('/tmp/minimal.parquet', engine='pyarrow')

~/.pyenv/versions/analytics-3.7/lib/python3.7/site-packages/pandas/io/parquet.py in read_parquet(path, engine, columns, **kwargs)
    294 
    295     impl = get_engine(engine)
--> 296     return impl.read(path, columns=columns, **kwargs)

~/.pyenv/versions/analytics-3.7/lib/python3.7/site-packages/pandas/io/parquet.py in read(self, path, columns, **kwargs)
    123         kwargs["use_pandas_metadata"] = True
    124         result = self.api.parquet.read_table(
--> 125             path, columns=columns, **kwargs
    126         ).to_pandas()
    127         if should_close:

~/.pyenv/versions/analytics-3.7/lib/python3.7/site-packages/pyarrow/array.pxi in pyarrow.lib._PandasConvertible.to_pandas()

~/.pyenv/versions/analytics-3.7/lib/python3.7/site-packages/pyarrow/table.pxi in pyarrow.lib.Table._to_pandas()

~/.pyenv/versions/analytics-3.7/lib/python3.7/site-packages/pyarrow/pandas_compat.py in table_to_blockmanager(options, table, categories, ignore_metadata)
    642         column_indexes = pandas_metadata.get('column_indexes', [])
    643         index_descriptors = pandas_metadata['index_columns']
--> 644         table = _add_any_metadata(table, pandas_metadata)
    645         table, index = _reconstruct_index(table, index_descriptors,
    646                                           all_columns)

~/.pyenv/versions/analytics-3.7/lib/python3.7/site-packages/pyarrow/pandas_compat.py in _add_any_metadata(table, pandas_metadata)
    965                 raw_name = 'None'
    966 
--> 967         idx = schema.get_field_index(raw_name)
    968         if idx != -1:
    969             if col_meta['pandas_type'] == 'datetimetz':

~/.pyenv/versions/analytics-3.7/lib/python3.7/site-packages/pyarrow/types.pxi in pyarrow.lib.Schema.get_field_index()

~/.pyenv/versions/analytics-3.7/lib/python3.7/site-packages/pyarrow/lib.cpython-37m-x86_64-linux-gnu.so in string.from_py.__pyx_convert_string_from_py_std__in_string()

TypeError: expected bytes, dict found
```
#### Problem description

A parquet file written with the `fastparquet` backend cannot be converted back to a pandas data frame when read with the `pyarrow` implementation. Conversion fails with the shown Exception, which seems to be part of applying the pandas meta data.

#### Expected Output

Successful conversion.

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

<details>
INSTALLED VERSIONS
------------------
commit           : None
python           : 3.7.4.final.0
python-bits      : 64
OS               : Linux
OS-release       : 4.19.69-1-lts
machine          : x86_64
processor        : 
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 0.25.1
numpy            : 1.17.0
pytz             : 2019.1
dateutil         : 2.8.0
pip              : 19.2.1
setuptools       : 41.0.1
Cython           : None
pytest           : 5.0.1
hypothesis       : 4.32.2
sphinx           : None
blosc            : None
feather          : None
xlsxwriter       : 1.1.8
lxml.etree       : 4.4.0
html5lib         : None
pymysql          : None
psycopg2         : 2.8.3 (dt dec pq3 ext lo64)
jinja2           : 2.10.1
IPython          : 7.7.0
pandas_datareader: None
bs4              : None
bottleneck       : None
fastparquet      : 0.3.2
gcsfs            : None
lxml.etree       : 4.4.0
matplotlib       : None
numexpr          : 2.6.9
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : 0.14.1
pytables         : None
s3fs             : 0.3.1
scipy            : None
sqlalchemy       : 1.2.19
tables           : 3.5.2
xarray           : None
xlrd             : None
xlwt             : None
xlsxwriter       : 1.1.8
</details>
