Test commit: inspect the env. vars. Travis uses.

This is sniffing around towards googleapis#2277, to see how much info
we can use to restrict the tests we run.

.travis.yml

@@ -1,35 +1,5 @@
 language: python
 sudo: false
 
-install:
-  - pip install --upgrade pip
-  - pip install --upgrade tox
-
 script:
-  - tox -e py27
-  - tox -e py34
-  - tox -e lint
-  - tox -e cover
-  - tox -e system-tests
-  - tox -e system-tests3
-  - scripts/update_docs.sh
-
-after_success:
-  - tox -e coveralls
-
-deploy:
-  provider: pypi
-  user: silvolu
-  password:
-    secure: keSFPLzVj/yAAJ8kw4m+U5kpIiGqubpDqhcHPlGAvMohFMIO4D8ffgCqJdbhQshTtb/wiS5ajK1KNpEzq4BKD/5oRXuj/sIRTMENzX/azUXkT/bADLEGocyfE4/NAGQ9mcDOmHntjt7UUhYN6H87rgex22er4V1vD5tGf5Kc1HU=
-  on:
-    tags: true
-    repo: GoogleCloudPlatform/google-cloud-python
-    # until this is fixed: https://github.com/travis-ci/travis-ci/issues/1675
-    all_branches: true
-  # 'bdist_wheel' builds disabled until #1879 et al. are resolved.
-  distributions: "sdist"
-
-cache:
-  directories:
-    - ${HOME}/.cache/pip
+  - python scripts/print_travis.py

scripts/print_travis.py

@@ -0,0 +1,9 @@
+import os
+
+our_keys = sorted(key for key in os.environ.keys()
+                  if 'travis' in key.lower())
+if our_keys:
+    for key in our_keys:
+        print('%s: %s' % (key, os.getenv(key)))
+else:
+    print('No keys here, sorry')