DataFrame() returns an empty DataFrame, if DatetimeIndex with timezone-info and column label are passed
#### Problem description
Converting a DatetimeIndex to Dataframe will result in different behaviors, depending on whether DatetimeIndex is **timezone-naive** or **timezone-aware**. This issue **only happens if columns label is provided**.

##### Input of Example 1: DatetimeIndex with timezone-info.
```python
import pandas as pd
start_dt2 = pd.to_datetime('20180101T10:00:00')
start_dt2 = start_dt2.tz_localize('Asia/Singapore')
end_dt2 = pd.to_datetime('20180101T10:03:00')
end_dt2 = end_dt2.tz_localize('Asia/Singapore')
date_range2 = pd.date_range(start_dt2, end_dt2, freq='T')
print(date_range2, '\n')

df2 = pd.DataFrame(date_range2, columns=['timestamps'])
print(df2)
```

##### Output of Example1: an empty DataFrame.
```python
DatetimeIndex(['2018-01-01 10:00:00+08:00', '2018-01-01 10:01:00+08:00',
               '2018-01-01 10:02:00+08:00', '2018-01-01 10:03:00+08:00'],
              dtype='datetime64[ns, Asia/Singapore]', freq='T') 

Empty DataFrame
Columns: [timestamps]
Index: [] 
```

##### Input of Example 2: DatetimeIndex is timezone-naive.
```python
start_dt = pd.to_datetime('20180101T10:00:00')
end_dt = pd.to_datetime('20180101T10:03:00')
date_range1 = pd.date_range(start_dt, end_dt, freq='T')
print(date_range1, '\n')

df1 = pd.DataFrame(date_range1, columns=['timestamps'])
print(df1)
```

##### Output of Example2: DataFrame returned.
```python
DatetimeIndex(['2018-01-01 10:00:00', '2018-01-01 10:01:00',
               '2018-01-01 10:02:00', '2018-01-01 10:03:00'],
              dtype='datetime64[ns]', freq='T') 

           timestamps
0 2018-01-01 10:00:00
1 2018-01-01 10:01:00
2 2018-01-01 10:02:00
3 2018-01-01 10:03:00 
```

The above two examples include the **argument columns=['timestamp']**. However, if we simply convert the DatetimeIndex (timezone-aware) with input argument as a dictionary object, it returns a DataFrame as shown in the example 2 above.

##### Input of Example 3: DatetimeIndex with timezone-info, passed as part of a dictionary.
```python
start_dt3 = pd.to_datetime('20180101T10:00:00')
start_dt3 = start_dt3.tz_localize('Asia/Singapore')
end_dt3 = pd.to_datetime('20180101T10:03:00')
end_dt3 = end_dt3.tz_localize('Asia/Singapore')
date_range3 = pd.date_range(start_dt3, end_dt3, freq='T')
print(date_range3, '\n')

df3 = pd.DataFrame({"timestamps": date_range3})
print(df3)
```

##### Output of Example3: DataFrame returned.
```python
DatetimeIndex(['2018-01-01 10:00:00+08:00', '2018-01-01 10:01:00+08:00',
               '2018-01-01 10:02:00+08:00', '2018-01-01 10:03:00+08:00'],
              dtype='datetime64[ns, Asia/Singapore]', freq='T') 

                 timestamps
0 2018-01-01 10:00:00+08:00
1 2018-01-01 10:01:00+08:00
2 2018-01-01 10:02:00+08:00
3 2018-01-01 10:03:00+08:00
```

### Question
Shouldn't the Example 1 returns a non-empty DataFrame which agrees with the output Example 3?  As I expect the outputs will be consistent, regardless of the timezone-info or timezone-naive of DatetimeIndex. Thank you.

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

<details>

INSTALLED VERSIONS
------------------
commit: None
python: 3.5.2.final.0
python-bits: 64
OS: Darwin
OS-release: 16.7.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: en_US.UTF-8
LANG: en_US.UTF-8
LOCALE: en_US.UTF-8

pandas: 0.22.0
pytest: 3.0.5
pip: 9.0.1
setuptools: 27.2.0
Cython: 0.25.2
numpy: 1.12.1
scipy: 0.19.0
pyarrow: None
xarray: None
IPython: 5.1.0
sphinx: 1.5.1
patsy: 0.4.1
dateutil: 2.6.0
pytz: 2016.10
blosc: 1.5.1
bottleneck: 1.2.1
tables: 3.3.0
numexpr: 2.6.2
feather: None
matplotlib: 2.0.2
openpyxl: 2.4.0
xlrd: 1.0.0
xlwt: 1.1.2
xlsxwriter: 0.9.6
lxml: 3.6.4
bs4: 4.5.1
html5lib: None
sqlalchemy: 1.1.4
pymysql: None
psycopg2: None
jinja2: 2.9.5
s3fs: None
fastparquet: None
pandas_gbq: None
pandas_datareader: 0.2.1
None

</details>
  