The target all includes setup to install golint, goveralls before executing build and coverage

[Biswajee]

Expected: The command make executes successfully.

Actual: The command make fails with /bin/sh: 1: goveralls: not found

Potential reason: The Makefile has the .PHONY target: all that may execute the targets: build, test, coverage. However, the command make fails as the prerequisites are not downloaded before executing the targets.

What changes were made in the PR:

1. Removed unnecessary strings attached with the .PHONY target.
2. Added the target setup in the all target so that golint and goveralls are installed before executing the build and coverage targets.