add support for goracle (github.com/tgulacsi/goracle/godrv)

GOSQLTEST_MYSQL_USER=user GOSQLTEST_MYSQL_PASS=pass GOSQLTEST_ORACLE=user/pass@XE go test -v
=== RUN TestBlobs_SQLite
--- PASS: TestBlobs_SQLite (0.00 seconds)
=== RUN TestBlobs_MyMySQL
--- PASS: TestBlobs_MyMySQL (0.02 seconds)
=== RUN TestBlobs_GoMySQL
--- PASS: TestBlobs_GoMySQL (0.02 seconds)
=== RUN TestBlobs_PQ
skipping test; no Postgres running on localhost:5432
--- PASS: TestBlobs_PQ (0.00 seconds)
=== RUN TestBlobs_Oracle
--- PASS: TestBlobs_Oracle (0.32 seconds)
=== RUN TestManyQueryRow_SQLite
--- PASS: TestManyQueryRow_SQLite (1.11 seconds)
=== RUN TestManyQueryRow_MyMySQL
--- PASS: TestManyQueryRow_MyMySQL (4.59 seconds)
=== RUN TestManyQueryRow_GoMySQL
--- PASS: TestManyQueryRow_GoMySQL (3.56 seconds)
=== RUN TestManyQueryRow_PQ
skipping test; no Postgres running on localhost:5432
--- PASS: TestManyQueryRow_PQ (0.00 seconds)
=== RUN TestManyQueryRow_Oracle
--- PASS: TestManyQueryRow_Oracle (6.49 seconds)
=== RUN TestTxQuery_SQLite
--- PASS: TestTxQuery_SQLite (0.00 seconds)
=== RUN TestTxQuery_MyMySQL
--- PASS: TestTxQuery_MyMySQL (0.02 seconds)
=== RUN TestTxQuery_GoMySQL
--- PASS: TestTxQuery_GoMySQL (0.02 seconds)
=== RUN TestTxQuery_PQ
skipping test; no Postgres running on localhost:5432
--- PASS: TestTxQuery_PQ (0.00 seconds)
=== RUN TestTxQuery_Oracle
--- PASS: TestTxQuery_Oracle (0.32 seconds)
=== RUN TestPreparedStmt_SQLite
--- PASS: TestPreparedStmt_SQLite (0.21 seconds)
=== RUN TestPreparedStmt_MyMySQL
--- PASS: TestPreparedStmt_MyMySQL (0.12 seconds)
=== RUN TestPreparedStmt_GoMySQL
--- PASS: TestPreparedStmt_GoMySQL (0.10 seconds)
=== RUN TestPreparedStmt_PQ
skipping test; no Postgres running on localhost:5432
--- PASS: TestPreparedStmt_PQ (0.00 seconds)
=== RUN TestPreparedStmt_Oracle
--- PASS: TestPreparedStmt_Oracle (0.88 seconds)
PASS
ok      sqltest 17.834s