.travis.yml: specify osx images (#95)

* .travis.yml:specify osx images

* remove allow_failures

* don't specify core num

.travis.yml

@@ -41,16 +41,11 @@ matrix:
       env: Tr_Compiler_Version="default"
       dist: trusty # broken compiler on 12.04
     - os: osx
-      #osx_image: xcode6.4 # seems broken and has lower priority in queue than default one
-      env: Tr_Xcode_Version="default"
-      #env: Tr_Xcode_Version="6.4"
-      # https://docs.travis-ci.com/user/osx-ci-environment/#OS-X-Version
-      # https://github.com/Homebrew/brew/blob/master/docs/Installation.md#requirements
-  fast_finish: true
-  allow_failures:
+      osx_image: xcode9.2
+      env: Tr_Xcode_Version="9.2"
     - os: osx
-    # it's not really acceptable to wait 40 minutes or sometimes up to even 3 hours
-    # for the result just because the queue for mac is always so long
+      osx_image: xcode9.3beta
+      env: Tr_Xcode_Version="9.3beta"
 
 git:
   submodules: false
@@ -76,10 +71,10 @@ before_install:
 
 script:
 # ALL THE BUILD COMMANDS HERE
-  - if [ "$TRAVIS_OS_NAME" = "linux" ] && [ "$(echo "$CC" | grep 'clang')" = "" ]; then mk/linux/build-zg.sh -c 4; fi
-  - if [ "$TRAVIS_OS_NAME" = "linux" ] && [ "$(echo "$CC" | grep 'clang')" != "" ]; then mk/linux/build-zg.sh -w -c 4; fi
+  - if [ "$TRAVIS_OS_NAME" = "linux" ] && [ "$(echo "$CC" | grep 'clang')" = "" ]; then mk/linux/build-zg.sh; fi
+  - if [ "$TRAVIS_OS_NAME" = "linux" ] && [ "$(echo "$CC" | grep 'clang')" != "" ]; then mk/linux/build-zg.sh -w; fi
   # ^ -w may be removed on more modern dist: than trusty, problems related with 'new wx+clang+old gcc'
-  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then mk/macos/build-zg.sh -c 4; fi
+  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then mk/macos/build-zg.sh; fi
 
 # https://docs.travis-ci.com/user/notifications/#IRC-notification
 notifications:
@@ -89,5 +84,7 @@ notifications:
     skip_join: true
     use_notice: true
     on_success: change
+    on_error: always
+    on_failure: change
     template:
       - "[%{repository_name}#%{branch}@%{commit}] %{author}: %{message} %{build_url}"