Add Clear Containers 3.0 support

[jcvenegas]

This PR adds support for:

Use docker to run osbuilder scripts is optional:

Now is optional use docker to build the kernel and image. Use docker allows to build and image and kernel without install all the dependencies (rpm,gcc,bc,losetup). If docker is wanted to use osbuilder scripts export the variable USE_DOCKER=true

USE_DOCKER=true
make rootfs
make image
make kernel-src
make kernel

ae26e6f osbuilder: allow to build images without docker 0198c4e Makefile: add check-deps target 8e0df1c osbuilder: check if yum or dnf is installed 6b7f2fd image-builder: Use a local mount directory. de69dfc osbuilder: generate dnf config file in cwd

Fixes: #12

Check DEBUG env variable to show bash traces.

0291fc8 build: Add DEBUG env variable for osbuilder scripts Fixes: #13

Reduce default image size to 50MB

8456741 osbuilder: Only use coreutils-bin 79c0a76 image-builder: Reduce default image size to 50MB Fixes: #14

Use URL env variable to change default clearlinux rpm repository.

ba666f0 osbuilder: add env variable to change URL repository Fixes: #15

add support for ci scripts to tests in semaphoreci

7059bc5 ci: add semaphoreci setup eb2822a ci: Run clear containers integration tests

Fixes: #16

Update kernel to pull the latest version doing make kernel-src

4b17f86 kernel: pull latest kernel. Fixes: #2

Clear containers image must inlcude clear-containers-agent

18fa103 pakages: Install clear-containers-agent Fixes: #17

[jcvenegas]

https://semaphoreci.com/jcvenega/osbuilder/branches/cc30/builds/5 PASS

[jcvenegas]

@mcastelino @eadamsintel @jodh-intel could you please take a look to this PR. ?

[jcvenegas]

@jodh-intel thanks for the review, changes applied.

[jcvenegas]

@jodh-intel @mcastelino any other comment ?

[jodh-intel]

lgtm