cannot use cli.StringFlag literal (type cli.StringFlag) as type cli.Flag in array or slice literal

[rnubel]

This issue is for documenting the fix to the above error -- if you are trying to install pgmgr from a folder where Go module support is not found, you may see this error as the cli dependency was not stable. In #46, I moved pgmgr to use Go modules to lock down its dependencies, so the fix for this is to install the tool with modules turned on:

GO111MODULE=on go get github.com/rnubel/pgmgr

This workaround should become unnecessary once Go changes its default setting for GO11MODULE to on, which should be in Go 1.14 or so.