travis: Switch to docker based builds

This requires to have distro specific install scripts and build.sh
script.

For now ibmswtpm2 is compiled just for native builds (depends on gcc,
compiled natively). libtmps/swtpm could be used.

Signed-off-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Bruno Meneguele <bmeneg@redhat.com>(Fedora,CentOS 8(RHEL actually))
[zohar@linux.ibm.com: removed debugging in travis/fedora.sh]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

travis/alpine.sh

@@ -0,0 +1,50 @@
+#!/bin/sh
+# Copyright (c) 2020 Petr Vorel <pvorel@suse.cz>
+set -ex
+
+if [ -z "$CC" ]; then
+	echo "missing \$CC!" >&2
+	exit 1
+fi
+
+case "$TSS" in
+ibmtss) echo "No IBM TSS package, will be installed from git" >&2; TSS=;;
+tpm2-tss) TSS="tpm2-tss-dev";;
+'') echo "Missing TSS!" >&2; exit 1;;
+*) echo "Unsupported TSS: '$TSS'!" >&2; exit 1;;
+esac
+
+# ibmswtpm2 requires gcc
+[ "$CC" = "gcc" ] || CC="gcc $CC"
+
+apk update
+
+apk add \
+	$CC $TSS \
+	asciidoc \
+	attr \
+	attr-dev \
+	autoconf \
+	automake \
+	diffutils \
+	docbook-xml \
+	docbook-xsl \
+	keyutils-dev \
+	libtool \
+	libxslt \
+	linux-headers \
+	make \
+	musl-dev \
+	openssl \
+	openssl-dev \
+	pkgconfig \
+	procps \
+	sudo \
+	wget \
+	which \
+	xxd
+
+if [ ! "$TSS" ]; then
+	apk add git
+	../tests/install-tss.sh
+fi