[ci] bump Azure image versions (#2822)

* bump Azure image versions

* fixed Windows builds

.ci/setup.sh

@@ -4,7 +4,7 @@ if [[ $OS_NAME == "macos" ]]; then
     if  [[ $COMPILER == "clang" ]]; then
         brew install libomp
         if [[ $AZURE == "true" ]]; then
-            sudo xcode-select -s /Applications/Xcode_8.3.3.app/Contents/Developer
+            sudo xcode-select -s /Applications/Xcode_9.4.1.app/Contents/Developer
         fi
     else  # gcc
         if [[ $TASK != "mpi" ]]; then

.vsts-ci.yml

@@ -19,7 +19,7 @@ jobs:
   variables:
     COMPILER: gcc
   pool:
-    vmImage: 'ubuntu-16.04'
+    vmImage: 'ubuntu-latest'
   container: ubuntu1404
   strategy:
     maxParallel: 6
@@ -74,7 +74,7 @@ jobs:
   variables:
     COMPILER: clang
   pool:
-    vmImage: 'macOS-10.13'
+    vmImage: 'macOS-10.14'
   strategy:
     maxParallel: 3
     matrix:

python-package/README.rst

@@ -22,7 +22,7 @@ For **Linux** users, **glibc** >= 2.14 is required.
 
 For **macOS** (we provide wheels for 3 newest macOS versions) users:
 
-- Starting from version 2.2.1, the library file in distribution wheels is built by the **Apple Clang** (Xcode_8.3.3) compiler. This means that you don't need to install the **gcc** compiler anymore. Instead of that you need to install the **OpenMP** library, which is required for running LightGBM on the system with the **Apple Clang** compiler. You can install the **OpenMP** library by the following command: ``brew install libomp``.
+- Starting from version 2.2.1, the library file in distribution wheels is built by the **Apple Clang** (Xcode_8.3.3 for versions 2.2.1 - 2.3.1, and Xcode_9.4.1 from version 2.3.2) compiler. This means that you don't need to install the **gcc** compiler anymore. Instead of that you need to install the **OpenMP** library, which is required for running LightGBM on the system with the **Apple Clang** compiler. You can install the **OpenMP** library by the following command: ``brew install libomp``.
 
 - For version smaller than 2.2.1 and not smaller than 2.1.2, **gcc-8** with **OpenMP** support must be installed first. Refer to `Installation Guide <https://github.com/microsoft/LightGBM/blob/master/docs/Installation-Guide.rst#gcc>`__ for installation of **gcc-8** with **OpenMP** support.