Clone repository outside of your GOPATH.
# Clone the provider plugin sources
$ mkdir -p ~/Projects; cd ~/Projects
$ git clone git@github.com:cathive/terraform-provider-routeros.git
Enter the provider directory and build the provider.
# Build the provider plugin
$ cd ~/Projects/terraform-provider-routeros
$ make build
# Now make the plugin locally available
# OS represents your operating system (e.g. windows, darwin, linux) and
# ARCH represents your operating system's architecture (most likely: amd64)
$ cp $GOPATH/bin/terraform-provider-routeros ~/.terraform.d/plugins/${OS}_${ARCH}/
If you're building the provider, follow the instructions to install it as a plugin.
After placing it into your plugins directory, run terraform init
to initialize it.