Travis-CI: Use Android NDK r13b specifically
authorDavid Neto <dneto@google.com>
Wed, 11 Jul 2018 19:31:36 +0000 (15:31 -0400)
committerDavid Neto <dneto@google.com>
Thu, 12 Jul 2018 16:02:26 +0000 (12:02 -0400)
commit3541d8a5a0126260c3313982d698c6600c320868
tree65b2240b73888c715fab5532bac9e13fd310834f
parent8dafeab47e60ea23e42bbb45f2983c9bb14ccdc5
Travis-CI: Use Android NDK r13b specifically

The Travis-CI bot downloads a copy of the Android NDK.  The source
we get it from recently updated to Android NDK r17b.  However,
the android.toolchain.cmake file does not know how to parse the
Android native API level from that version of the NDK.  So check
out the NDK r13b version that we were using until yesterday.

Fixes #1439
.travis.yml