Update to Bazel 0.26 instead.

test_coverage_on fails for some mysterious reason that seems unrelated to the cleanup crusade I'm pursuing at the moment.

Author: lberki

.travis.yml

@@ -20,9 +20,9 @@ env:
   # See https://github.com/bazelbuild/rules_scala/pull/622
   # we want to test the last release
   #- V=0.16.1 TEST_SCRIPT=test_lint.sh
-  - V=0.28.1 TEST_SCRIPT=test_rules_scala
+  - V=0.26 TEST_SCRIPT=test_rules_scala
     #- V=0.14.1 TEST_SCRIPT=test_intellij_aspect.sh
-  - V=0.28.1 TEST_SCRIPT=test_reproducibility
+  - V=0.26 TEST_SCRIPT=test_reproducibility
 
 
 before_install: