support for 2018 acs data

[mr-fuller]

No description provided.

[MaxGhenis]

I think these two changes to https://github.com/datamade/census/blob/master/census/tests/test_census.py should address the build failures:

1. Specify 2017 in the test that checks for La Canada Flintridge with 2017 data.

Replace this line:

census/census/tests/test_census.py

Line 109 in 4f0244c

self._client.acs5.get('NAME', geo=geo)[0]['NAME'],

with:

            self._client.acs5.get('NAME', geo=geo, year=2017)[0]['NAME'],

2. Update the following instances of 115th Congress to 116th Congress:

census/census/tests/test_census.py

Lines 164 to 167 in 4f0244c

	'Congressional District 6 (115th Congress), Maryland'),
	('state_congressional_district',
	'Congressional District 6 (115th Congress), Maryland'),
	('state_legislative_district_upper',

census/census/tests/test_census.py

Lines 181 to 182 in 4f0244c

	('state_congressional_district',
	'Congressional District 6 (115th Congress), Maryland'),

[fgregg]

agree @MaxGhenis

[fgregg]

closed by #89