Add go 1.10 tests && Bump task version

[hanzei]

• Add go 1.10 to CI
• Bump task version to 2.0.1
• Fix go version settings to String format.

Building a Go Project - Travis CI

Note that, in order to choose Go 1.10, you must use go: "1.10" (a string), not go: 1.10 (a float). Using a float results in the use of Go 1.1.