Revert "Added size option to 'bulk' thread pool"

This reverts commit edbbd9e.

Upgrade Elasticsearch to version 5.5.1.

Signed-off-by: Paulo Pires <[email protected]>

Upgrade Elasticsearch to version 5.5.0.

Signed-off-by: Paulo Pires <[email protected]>

Upgrade Elasticsearch to version 5.4.3.

Signed-off-by: Paulo Pires <[email protected]>

Upgrade Elasticsearch to version 5.4.2.

Signed-off-by: Paulo Pires <[email protected]>

Upgrade Elasticsearch to version 5.4.1.

Signed-off-by: Paulo Pires <[email protected]>

Move to Alpine 3.6 and OpenJDK JRE 8u131.

Signed-off-by: Paulo Pires <[email protected]>

Upgrade Elasticsearch to version 5.4.0.

Signed-off-by: Paulo Pires <[email protected]>

Upgrade Elasticsearch to version 5.3.2.

Signed-off-by: Paulo Pires <[email protected]>

Upgrade Elasticsearch to version 5.3.1.

Signed-off-by: Paulo Pires <[email protected]>