Update .travis.yml

Author: wjo1212

.travis.yml

@@ -1,8 +1,6 @@
 language: python
 python:
-  - "2.6"
   - "2.7"
-  - "3.3"
   - "3.4"
   - "3.5"
   - "3.6"
@@ -23,8 +21,6 @@ install:
 
 script:
   - python tests/ut/test_util.py
-  - python tests/etl_test/test_case.py
-  - python tests/cli_config_check/test_case.py
   - python tests/sample.py
   - python tests/integration_test/test_logtail_config.py
   - python tests/integration_test/test_entity.py