Merge pull request libgit2#4962 from libgit2/ethomson/ci_nightly

ci: return coverity to the nightlies

Author: ethomson

azure-pipelines/coverity.yml

@@ -186,3 +186,22 @@ jobs:
        CMAKE_OPTIONS=-DUSE_HTTPS=OpenSSL
        RUN_INVASIVE_TESTS=true
        SKIP_PROXY_TESTS=true
+
+- job: coverity
+  displayName: 'Coverity'
+  pool:
+    vmImage: 'Ubuntu 16.04'
+  steps:
+  - task: Docker@0
+    displayName: Build
+    inputs:
+      action: 'Run an image'
+      imageName: 'libgit2/trusty-openssl:latest'
+      volumes: |
+       $(Build.SourcesDirectory):/src
+       $(Build.BinariesDirectory):/build
+      envVars: |
+       COVERITY_TOKEN=$(COVERITY_TOKEN)
+      workDir: '/build'
+      containerCommand: '/src/ci/coverity.sh'
+      detached: false