BUG: to_html misses truncation indicators (...) when index=False and max_cols < len(columns)

[simonjayhawkins]

Code Sample

np.random.seed(seed=0)
df = pd.DataFrame(np.random.randn(2,5))
df.to_html(max_cols=4, index=False)

Problem description

similar to #15019 with max_cols instead of max_rows

Output

0	1	3	...	4
1.764052	0.400157	2.240893	1.867558
-0.977278	0.950088	-0.103219	0.410599

Expected Output

0	1	...	3	4
1.764052	0.400157	...	2.240893	1.867558
-0.977278	0.950088	...	-0.103219	0.410599

Output of pd.show_versions()

INSTALLED VERSIONS

commit: None
python: 3.6.5.final.0
python-bits: 64
OS: Windows
OS-release: 10
machine: AMD64
processor: Intel64 Family 6 Model 58 Stepping 9, GenuineIntel
byteorder: little
LC_ALL: None
LANG: None
LOCALE: None.None

pandas: 0.23.0
pytest: 3.5.1
pip: 10.0.1
setuptools: 39.1.0
Cython: 0.28.2
numpy: 1.14.3
scipy: 1.1.0
pyarrow: None
xarray: None
IPython: 6.4.0
sphinx: 1.7.4
patsy: 0.5.0
dateutil: 2.7.3
pytz: 2018.4
blosc: None
bottleneck: 1.2.1
tables: 3.4.3
numexpr: 2.6.5
feather: None
matplotlib: 2.2.2
openpyxl: 2.5.3
xlrd: 1.1.0
xlwt: 1.3.0
xlsxwriter: 1.0.4
lxml: 4.2.1
bs4: 4.6.0
html5lib: 1.0.1
sqlalchemy: 1.2.7
pymysql: None
psycopg2: None
jinja2: 2.10
s3fs: None
fastparquet: None
pandas_gbq: None
pandas_datareader: None