Update Travis CI files to account for new build dependencies

* Add Fedora 28 and Ubuntu 18.04 Dockerfile
* Add new build dependencies (for the ACRN tools)
* Change default Fedora version to 28

Signed-off-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>

.travis-dockerfiles/README.md

@@ -0,0 +1,80 @@
+# Build containers for Project ACRN
+
+## Introduction
+
+This folder contains a number of Dockerfile that include
+all the build tools and dependencies to build the ACRN Project
+components, i.e. the `acrn-hypervisor` and `acrn-devicemodel`
+
+The workflow is pretty simple and can be summarized in these few steps:
+
+1. Build the *build containers* based on your preferred OS
+1. Clone the Project ACRN repositories
+1. Start the build container and give it the repositories
+1. Build the Project ACRN components
+
+The pre-requisite is that you have Docker installed on your machine.
+Explaining how to install it on your system is beyond the scope of this
+document, please visit https://www.docker.com for detailed instructions.
+
+## Build the *build containers*
+
+Each `Dockerfile` in this repo has an extension that tells what Linux
+distribution it is based on. To build a container using any of those,
+use this command:
+```
+$ sudo docker build -t <container-name> -f Dockerfile.<baseos> .
+```
+
+As an example, to build a container based on CentOS 7, do:
+```
+$ sudo docker build -t centos7 -f Dockerfile.centos7 .
+```
+
+## Clone Project ACRN
+
+Follow these simple steps to clone the Project ACRN repositories
+```
+$ mkdir ~/acrn
+$ cd ~/acrn
+$ git clone https://github.com/projectacrn/acrn-hypervisor
+$ git clone https://github.com/projectacrn/acrn-devicemodel
+```
+
+## Start the build container
+
+Use this `~/acrn` folder and pass it on to your build container:
+```
+$ cd ~/acrn
+$ sudo docker run -ti -v $PWD:/root/acrn <container-name>
+```
+
+Using CentOS 7 again as an example, that gives us:
+```
+$ cd ~/acrn
+$ sudo docker run -ti -v $PWD:/root/acrn centos7
+```
+
+**Note:** if you encounter permission issues within the container (as it
+happens on a Fedora 27 host), try adding the `:z` parameter to the mount option.
+This will unlock the permission restriction (that comes from SElinux). Your
+command-line would then be:
+```
+$ cd ~/acrn
+$ sudo docker run -ti -v $PWD:/root/acrn:z centos7
+```
+
+## Build the ACRN components
+
+The steps above place you inside the container and give you access to
+the Project ACRN repositories you cloned earlier. You can now build any
+of the components. Here is an example:
+```
+# cd acrn-hypervisor
+# make PLATFORM=uefi RELEASE=1
+```
+
+You can do this for all build combinations and also try to build the `acrn-devicemodel`.
+All the build dependencies and tools are pre-installed in the container as well as a
+couple of useful tools (`git` and `vim`) so you can directly edit files to experiment
+from within the container.