Update .travis.yml

Author: ConfZ

.travis.yml

@@ -1,9 +1,14 @@
-  language: python
-  python:
-    - "3.6"
-  script:
-    - pytest
-  install:
-    - pip install -r requirements.txt
-  after_success:
-    - bash <(curl -s https://blackducksoftware.github.io/hub-detect/hub-detect.sh) --blackduck.hub.url="https://hubeval32.blackducksoftware.com" --blackduck.hub.username="ntu" --blackduck.hub.password="ntu@2018" --blackduck.hub.trust.cert=true --detect.policy.check=true
+
+language: python
+python:
+  - "2.7"
+
+# command to install dependencies
+install:
+  - pip install -r requirements.txt
+
+script:
+  - pytest
+
+after_success:
+  - bash <(curl -s https://blackducksoftware.github.io/hub-detect/hub-detect.sh) --blackduck.hub.url="https://hubeval32.blackducksoftware.com" --blackduck.hub.username="ntu" --blackduck.hub.password="ntu@2018" --blackduck.hub.trust.cert=true --detect.policy.check=true