Merge branch 'maint-0.2.5' into maint-0.2.9

    - MAKEFLAGS="-j 2"

matrix:

  ## If one build in the matrix fails (e.g. if building withour Rust and Clang

  ## fails, but building with Rust and GCC is still going), then cancel the

  ## entire job early and call the whole thing a failure.

  fast_finish: true

  ## Uncomment to allow the build to report success (with non-required

  ## sub-builds continuing to run) if all required sub-builds have

  ## succeeded.  This is somewhat buggy currently: it can cause

  ## duplicate notifications and prematurely report success if a

  ## single sub-build has succeeded.  See

  ## https://github.com/travis-ci/travis-ci/issues/1696

  # fast_finish: true

  ## Uncomment the appropriate lines below to allow the build to

  ## report success even if some less-critical sub-builds fail and it

  ## seems likely to take a while for someone to fix it.  Currently

  ## Travis CI doesn't distinguish "all builds succeeded" from "some

  ## non-required sub-builds failed" except on the individual build's

  ## page, which makes it somewhat annoying to detect from the

  ## branches and build history pages.  See

  ## https://github.com/travis-ci/travis-ci/issues/8716

  allow_failures:

    # - env: RUST_OPTIONS="--enable-rust" TOR_RUST_DEPENDENCIES=true

    # - env: RUST_OPTIONS="--enable-rust --enable-cargo-online-mode

    # - compiler: clang

  ## Create explicit matrix entries to work around a Travis CI

  ## environment issue.  Missing keys inherit from the first list