travis: more cleanup (#3336)

* add links to build image update history

* remove cmake from apt

* remove bc from apt

* remove clang-format from apt

* test clang-format

* Revert "test clang-format"

This reverts commit b2f12da427.

* remove protobuf from apt

* Revert "remove protobuf from apt"

This reverts commit 9162c8800c.

* remove qt from apt

* test with versions which differ from what xenial provides

* Revert "test with versions which differ from what xenial provides"

This reverts commit 6192e58169.

* Revert "remove qt from apt"

This reverts commit 0d9aff1c4c.

* conditions v1 are the default now

https://blog.travis-ci.com/2018-07-18-build-stages-officially-released

* add new job names

https://docs.travis-ci.com/user/customizing-the-build/?utm_source=blog&utm_medium=web&utm_campaign=build_stages_ga#Naming-Jobs-within-Matrices

* disable mail

* clang-format version

* remove clang source

* cmake version

* macOS: remove clang-format

formatting only checked on linux build

* add compiler info

* cmake version2

* remove fast_finish

only useful if allowed failures are configured in the matrix:
https://docs.travis-ci.com/user/customizing-the-build/#fast-finishing

.appveyor.yml

@@ -97,6 +97,7 @@ build_script:
         $protodir = "c:\protobuf-release"
         $protoc = "c:\protobuf-release\bin\protoc.exe"
         $mysqldll = "c:\Program Files\MySQL\MySQL Server 5.7\lib\libmysql.dll"
+        cmake --version
         cmake .. -G "$env:cmake_generator" -T "$env:cmake_toolset" "-DCMAKE_PREFIX_PATH=c:/Qt/$env:qt_ver;$protodir;$zlibdir;$openssldir" "-DWITH_SERVER=1" "-DPROTOBUF_PROTOC_EXECUTABLE=$protoc" "-DMYSQLCLIENT_LIBRARIES=$mysqldll"
     - msbuild PACKAGE.vcxproj /p:Configuration=Release
     - ps: |
@@ -145,5 +146,6 @@ deploy:
       APPVEYOR_REPO_TAG_NAME: /([0-9]|[1-9][0-9])(\.([0-9]|[1-9][0-9])){2}$/    # regex to match semver naming convention for stable full releases
 
 
-# official validator for ".appveyor.yml" config file: https://ci.appveyor.com/tools/validate-yaml
-# appveyor config documentation: https://www.appveyor.com/docs/build-configuration/
+# Announcements of build image updates: https://www.appveyor.com/updates/
+# Official validator for ".appveyor.yml" config file: https://ci.appveyor.com/tools/validate-yaml
+# AppVeyor config documentation: https://www.appveyor.com/docs/build-configuration/