Last release compatible with Go 1.8

This is the last release compatible with Go 1.8. After 1.2.0, go-dockerclient requires Go 1.9 or higher.

This release includes the following changes:

• ca33ff2: Revert "travis: does 1.10.x work? :)"
• da22455: appveyor: Go 1.10
• 2e99a54: travis: does 1.10.x work? :)
• bddface: plugin: clear up the parameters definition for InstallPlugins
• 2ac0f35: plugin: fix year in license banner
• e2a58e4: authors: add Yosuke Otosu
• 7aea04c: Merge branch 'feature/plugins_api' of https://github.com/airking05/go-dockerclient
• 0d072dc: [Fix] tests
• fd34b2a: [Fix] comments for ci tests
• 011e905: [Fix] method/type comments & some bug fixes
• 13ebb77: appveyor: go 1.8.7, 1.9.4 and 1.10rc2
• fcb9d66: tar: use absolute path as srcPath when generating the tar stream
• e4f49da: [Add] full tests for plugin api
• 6b2bf29: [Add] some test func for plugins api
• 268ba48: [Clean] build lint error
• 7c9fb31: [Update] add json/yaml/toml tag
• 9ddbd64: [Add] plugin api impl
• a2e072c: authors: add Sebastian Borza
• eb67e9e: Merge branch 'online_cpus' of https://github.com/sebito91/go-dockerclient
• b6edff4: updating based on feedback
• 7199630: testing: fix the build
• ddfd07a: Merge pull request #711 from cezarsa/fixrace
• 23cc4f7: adding in swarm ContainerStatus update
• 6e8e612: adding in online_cpus as of docker v17.05 stats update
• 26cad7b: testing: fix race condition reading data from containers
• f21b764: license: happy new year!
• 385221b: Merge branch 'master' of https://github.com/shutefan/go-dockerclient
• 59db691: Return ContainerNotRunning when trying to kill stopped container
• baaca7f: auth: skip empty config.auth entries
• fac48ff: authors: add Denis Makogon
• 213c831: Merge branch 'issue/705' of https://github.com/denismakogon/go-dockerclient
• c8359a5: Fixing Windows stuff
• 560fb41: Adding comment for WithTransport
• d35e79d: Trying to address appveyor issues
• c13236a: Refactor base method to make it become reusable whenever it's needed
• a8f5e91: Fixing tests
• f6bd8f3: Make HTTP client transport replacable
• 05df806: Merge branch 'parse-error' of https://github.com/knight42/go-dockerclient
• cbef7f6: fix: parse the error message
• 413e380: Merge pull request #701 from cezarsa/fixrace
• 883a709: testing: fix data race when reading container state in some handlers
• 5030de4: Merge pull request #700 from itshacki/fix/missing-omitempty-in-hostconfig
• 526702c: Add omitempty to host config MemorySwappiness opt
• df05870: testing: fix image tag and inspect using image id instead of name
• f3d2516: container: make StopContainer test more reliable