add sqlite3 to docker image for option "-console"

[yuanyangwu]

fix #93

Problem

$ sudo docker run --rm -it -v $(pwd):/tmp textql -console test.csv                                    
2018/05/10 09:32:30 Console requested but unable to locate `sqlite3` program on $PATH

Root cause

sqlite3 is not included in Docker image

Solution

Install sqlite3 command in Dockerfile

Test

vagrant@k8smaster:~/dev/textql$ cat test.csv
first_name,last_name,ssn
John,Barry,123456
Kathy,Smith,687987
Bob,McCornick,3979870

# test "-sql"
vagrant@k8smaster:~/dev/textql$ sudo docker run --rm -it -v $(pwd):/tmp textql -header -sql 'SELECT * FROM test' test.csv
John,Barry,123456
Kathy,Smith,687987
Bob,McCornick,3979870

# test "-console"
vagrant@k8smaster:~/dev/textql$ sudo docker run --rm -it -v $(pwd):/tmp textql -header -console test.csv
SQLite version 3.16.2 2017-01-06 16:32:41
Enter ".help" for usage hints.
sqlite> SELECT * FROM test;
John|Barry|123456
Kathy|Smith|687987
Bob|McCornick|3979870
sqlite> SELECT * FROM test WHERE ssn>200000;
Kathy|Smith|687987
Bob|McCornick|3979870
sqlite>
vagrant@k8smaster:~/dev/textql$