Merge #16610: [0.18] travis: Bump timeout from 50 minutes to 90, caching fixes

80cd3f0ba68ccba333f0bd5241c34f2f22cf1c48 travis: Bump timeout from 50 minutes to 90 (MarcoFalke)
5aac5e9b0311e41bd3c6a07d065eae0c47004814 travis: Bump second timeout to 33 minutes, Add rationale (MarcoFalke)
2c341e3471d300b940b83f0bb90b6bcee2fa5d38 travis: Properly cache and error on timeout (MarcoFalke)

Pull request description:

ACKs for top commit:
  fanquake:
    ACK 80cd3f0ba68ccba333f0bd5241c34f2f22cf1c48 - assuming Travis is happy.

Tree-SHA512: d903bff9407d0e07d81037f667645263ad96852ea66a1d9118365444a332e1bf8f5973ecf5ef862a9759614377409c12619a80b638bd6cde2695d6fb6532ff83

2 files changed, 0 insertions, 43 deletions

diff --git a/doc/README.md b/doc/README.md
index 8876ffdd72..b4fa933c8e 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -57,7 +57,6 @@ The Bitcoin repo's [root README](/README.md) contains relevant information on th
 - [Source Code Documentation (External Link)](https://dev.visucore.com/bitcoin/doxygen/)
 - [Translation Process](translation_process.md)
 - [Translation Strings Policy](translation_strings_policy.md)
-- [Travis CI](travis-ci.md)
 - [JSON-RPC Interface](JSON-RPC-interface.md)
 - [Unauthenticated REST Interface](REST-interface.md)
 - [Shared Libraries](shared-libraries.md)
diff --git a/doc/travis-ci.md b/doc/travis-ci.md
deleted file mode 100644
index 38085cec35..0000000000
--- a/doc/travis-ci.md
+++ /dev/null
@@ -1,42 +0,0 @@
-Travis CI
-=========
-
-Support for using travis-ci has been added in order to automate pull-testing.
-See [travis-ci.org](https://travis-ci.org/) for more info
-
-This procedure is different than the pull-tester that came before it in a few
-ways.
-
-There is nothing to administer. This is a major feature as it means
-that builds have no local state. Because there is no ability to login to the
-builders to install packages (tools, dependencies, etc), the entire build
-procedure must instead be controlled by a declarative script `.travis.yml`.
-This script declares each build configuration, creates virtual machines as
-necessary, builds, then discards the virtual machines.
-
-A build matrix is constructed to test a wide range of configurations, rather
-than a single pass/fail. This helps to catch build failures and logic errors
-that present on platforms other than the ones the author has tested. This
-matrix is defined in the build script and can be changed at any time.
-
-All builders use the dependency-generator in the [depends dir](/depends), rather than
-using apt-get to install build dependencies. This guarantees that the tester
-is using the same versions as Gitian, so the build results are nearly identical
-to what would be found in a final release. However, this also means that builds
-will fail if new dependencies are introduced without being added to the
-dependency generator.
-
-In order to avoid rebuilding all dependencies for each build, the binaries are
-cached and re-used when possible. Changes in the dependency-generator will
-trigger cache-invalidation and rebuilds as necessary.
-
-These caches can be manually removed if necessary. This is one of the very few
-manual operations that is possible with Travis, and it can be done by the
-Bitcoin Core committer via the Travis web interface.
-
-In some cases, secure strings may be needed for hiding sensitive info such as
-private keys or URLs. The travis client may be used to create these strings:
-http://docs.travis-ci.com/user/encryption-keys/
-
-For the details of the build descriptor, see the official docs:
-http://docs.travis-ci.com/user/build-configuration/