Increase .travis.yml consistency between repos

- aspnet/Universe#349
- minimize `dotnet` setup time; no need for caching
- `KOREBUILD_TEST_DNXCORE` env variable isn't used anymore
- no need for icu4c w/ current `dotnet` builds

.travis.yml

@@ -10,8 +10,10 @@ addons:
     - libssl-dev
     - libunwind8
     - zlib1g
-before_install:
+env:
-  - if test "$TRAVIS_OS_NAME" == "osx"; then brew update; brew install icu4c; brew install openssl; brew link --force openssl; fi
+  global:
+    - DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
+    - DOTNET_CLI_TELEMETRY_OPTOUT: 1
 mono:
   - 4.0.5
 os:
@@ -24,7 +26,7 @@ branches:
     - release
     - dev
     - /^(.*\/)?ci-.*$/
+before_install:
+  - if test "$TRAVIS_OS_NAME" == "osx"; then brew update; brew install openssl; ln -s /usr/local/opt/openssl/lib/libcrypto.1.0.0.dylib /usr/local/lib/; ln -s /usr/local/opt/openssl/lib/libssl.1.0.0.dylib /usr/local/lib/; fi
 script:
   - ./build.sh --quiet verify
-env:
-  - KOREBUILD_TEST_SKIPMONO=1