Add sqlite to tests and documentation

.gitignore

 composer.phar
-vendor/
+vendor/
+data.db

README.md

 
 ## Requirements
 
-  - PHP 7.0 or higher with PDO drivers for MySQL, PgSQL or SqlSrv enabled
+  - PHP 7.0 or higher with PDO drivers for MySQL, PgSQL, SqlSrv or SQLite enabled
   - MySQL 5.6 / MariaDB 10.0 or higher for spatial features in MySQL
   - PostGIS 2.0 or higher for spatial features in PostgreSQL 9.1 or higher
   - SQL Server 2012 or higher (2017 for Linux support)
+  - SQLite 3 or higher (has no geospatial support)
 
 ## Installation
 
 
 These are all the configuration options and their default value between brackets:
 
-- "driver": `mysql`, `pgsql` or `sqlsrv` (`mysql`)
-- "address": Hostname of the database server (`localhost`)
+- "driver": `mysql`, `pgsql`, `sqlsrv` or `sqlite` (`mysql`)
+- "address": Hostname (or filename) of the database server (`localhost`)
 - "port": TCP port of the database server (defaults to driver default)
 - "username": Username of the user connecting to the database (no default)
 - "password": Password of the user connecting to the database (no default)
 These limitation and constrains apply:
 
   - Primary keys should either be auto-increment (from 1 to 2^53) or UUID
-  - Composite primary or foreign keys are not supported
+  - Composite primary and composite foreign keys are not supported
   - Complex writes (transactions) are not supported
   - Complex queries calling functions (like "concat" or "sum") are not supported
   - Database must support and define foreign key constraints

docker/debian10/Dockerfile

 
 ARG DEBIAN_FRONTEND=noninteractive
 
-# install: php / mysql / postgres / tools / mssql deps
+# install: php / mysql / postgres / sqlite / tools / mssql deps
 RUN apt-get update && apt-get -y install \
 php-cli php-xml \
 mariadb-server mariadb-client php-mysql \
 postgresql php-pgsql \
 postgresql-11-postgis-2.5 \
+sqlite3 php-sqlite3 \
 git wget
 
 # install run script

docker/debian9/Dockerfile

 
 ARG DEBIAN_FRONTEND=noninteractive
 
-# install: php / mysql / postgres / tools / mssql deps
+# install: php / mysql / postgres / sqlite / tools / mssql deps
 RUN apt-get update && apt-get -y install \
 php-cli php-xml \
 mariadb-server mariadb-client php-mysql \
 postgresql php-pgsql \
 postgresql-9.6-postgis-2.3 \
+sqlite3 php-sqlite3 \
 git wget
 
 # install run script

docker/ubuntu16/Dockerfile

 
 ARG DEBIAN_FRONTEND=noninteractive
 
-# install: php / mysql / postgres / tools / mssql deps
+# install: php / mysql / postgres / sqlite / tools / mssql deps
 RUN apt-get update && apt-get -y install \
 php-cli php-xml \
 mariadb-server mariadb-client php-mysql \
 postgresql php-pgsql \
 postgresql-9.5-postgis-2.2 \
+sqlite3 php-sqlite3 \
 git wget \
 curl apt-transport-https debconf-utils sudo
 

docker/ubuntu18/Dockerfile

 
 ARG DEBIAN_FRONTEND=noninteractive
 
-# install: php / mysql / postgres / tools
+# install: php / mysql / postgres / sqlite / tools
 RUN apt-get update && apt-get -y install \
 php-cli php-xml \
 mysql-server mysql-client php-mysql \
 postgresql php-pgsql \
 postgresql-10-postgis-2.4 \
+sqlite3 php-sqlite3 \
 git wget
 
 # install locales

docker/ubuntu20/Dockerfile

 
 ARG DEBIAN_FRONTEND=noninteractive
 
-# install: php / mysql / postgres / tools
+# install: php / mysql / postgres / sqlite / tools
 RUN apt-get update && apt-get -y install \
 php-cli php-xml \
 mysql-server mysql-client php-mysql \
 postgresql php-pgsql \
 postgresql-12-postgis-3 \
+sqlite3 php-sqlite3 \
 git wget
 
 # install locales