Added test environment for Postgresql Executor

.travis.yml

@@ -1,13 +1,23 @@
 language: python
 python:
   - "3.7"
+services:
+  - postgresql
 install:
   - pip install codecov
   - pip install -r requirements.txt
   - pip install git+https://github.com/lux-org/lux-widget
   #- npm i lux-widget
+before_script:
+   - psql -c "ALTER USER postgres WITH PASSWORD 'lux';" -U postgres 
+   - psql -c "ALTER USER postgres WITH SUPERUSER;" -U postgres
+   - psql -c "ALTER DATABASE postgres OWNER TO travis;"
+   - psql -c "DROP schema public cascade;" -U postgres
+   - psql -c "CREATE schema public;" -U postgres
+   - psql -c "CREATE DATABASE postgres_db;" -U postgres
 # command to run tests
 script:
+  - python lux/data/upload_car_data.py
   - python -m pytest tests/*.py
   - pytest --cov-report term --cov=lux tests/
 after_success:

lux/data/upload_car_data.py

@@ -0,0 +1,37 @@
+import pandas as pd
+import psycopg2
+import csv
+
+import psycopg2
+conn = psycopg2.connect("host=localhost dbname=postgres_db user=postgres password=lux")
+cur = conn.cursor()
+cur.execute("""
+	DROP TABLE IF EXISTS car
+	""")
+#create car table in postgres database
+cur.execute("""
+    CREATE TABLE car(
+    name text,
+    milespergal numeric,
+    cylinders integer,
+    displacement numeric,
+    horsepower integer,
+    weight integer,
+    acceleration numeric,
+    year integer,
+    origin text
+)
+""")
+
+#open car.csv and read data into database
+with open('lux/data/car.csv', 'r') as f:
+	reader = csv.reader(f)
+	next(reader) # Skip the header row.
+	i = 0
+	for row in reader:
+		cur.execute(
+		"INSERT INTO car VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s)",
+		row
+	)
+
+conn.commit()

requirements.txt

@@ -10,5 +10,5 @@ Sphinx>=3.0.2
 sphinx-rtd-theme>=0.4.3
 lux-widget==0.1.0
 # Install only to use SQLExecutor
-# psycopg2>=2.8.5
-# psycopg2-binary>=2.8.5
+psycopg2>=2.8.5
+psycopg2-binary>=2.8.5