temporarily create and cache a release directory

I need to debug a deployment issue and that is a pain
when the build takes 40 minutes. Caching the final result
so that I can quickly try deploying.

Will undo this change when the deployment issue is resolved.

.travis.yml

@@ -1,13 +1,11 @@
-# errata:
-# - A travis bug causes caches to trample eachother when using the same
-#   compiler key (which we don't use anyway). This is worked around for now by
-#   replacing the "compilers" with a build name prefixed by the no-op ":"
-#   command. See: https://github.com/travis-ci/travis-ci/issues/4393
-# - sudo/dist/group are set so as to get Blue Box VMs, necessary for [loopback]
-#   IPv6 support
-
 sudo: required
 dist: trusty
 
+cache:
+  directories:
+    - release
+
 install: true
-script: ./reproducible_build.sh -t
+script:
+  - if [ ! -f release/lbrycrd-linux.zip ]; then  ./reproducible_build.sh -t; fi
+  - if [ ! -f release/lbrycrd-linux.zip ]; then mkdir -p release; zip -j release/lbrycrd-linux.zip src/lbrycrdd src/lbrycrd-cli src/lbrycrd-tx; fi