Try to add azure pipelines

.azure/azure-pipelines.yml

@@ -0,0 +1,42 @@
+variables:
+  protobuf-version: 3.7.1
+  lkg-rust-nightly: "2019-06-16"
+
+trigger:
+  - master
+
+strategy:
+  matrix:
+    linux-nightly:
+      image: ubuntu-16.04
+      toolchain: nightly-$(lkg-rust-nightly)
+      features: unstable
+      protobuf-platform: linux-x86_64
+    macos-nightly:
+      image: macos-10.13
+      toolchain: nightly-$(lkg-rust-nightly)
+      features: unstable
+      protobuf-platform: osx-x86_64
+    windows-nightly:
+      image: vs2017-win2016
+      toolchain: nightly-$(lkg-rust-nightly)
+      features: unstable
+      protobuf-platform: win64
+
+pool:
+  vmImage: $(image)
+
+steps:
+  - bash: |
+      set -e
+      curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain none
+      export PATH=$HOME/.cargo/bin:$PATH
+      rustup install --no-self-update $(toolchain)
+      rustup default $(toolchain)
+      rustc -Vv
+      echo "##vso[task.prependpath]$HOME/.cargo/bin"
+    displayName: Install Rust
+  - bash: cargo build
+    displayName: Build source
+  - bash: cargo test
+displayName: Run tests