Rename gooni to probe-cli

This is the command I used:
```
rg 'github.com/openobservatory/gooni' --files-with-matches \
    | xargs sed -i '' 's/github.com\/openobservatory\/gooni/github.com\/ooni\/probe-cli/g'
```

internal/database/database.go

@@ -4,7 +4,7 @@ import (
 	"github.com/apex/log"
 	"github.com/jmoiron/sqlx"
 	_ "github.com/mattn/go-sqlite3" // this is needed to load the sqlite3 driver
-	"github.com/openobservatory/gooni/internal/bindata"
+	"github.com/ooni/probe-cli/internal/bindata"
 	migrate "github.com/rubenv/sql-migrate"
 )
 

internal/database/models.go

@@ -7,7 +7,7 @@ import (
 
 	"github.com/apex/log"
 	"github.com/jmoiron/sqlx"
-	"github.com/openobservatory/gooni/utils"
+	"github.com/ooni/probe-cli/utils"
 	"github.com/pkg/errors"
 )