install swagger from source

First of all this removes the need for a network connection, second
renovate can update the version as it is tracked in go.mod.

However the real important part is that the binary downloads are
broken[1]. For some reason the swagger created with them does not
include all the type information for the examples. However when building
from source the same thing works fine.

[1] https://github.com/go-swagger/go-swagger/issues/2842

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

hack/install_swagger.sh

@@ -1,31 +0,0 @@
-#!/usr/bin/env bash
-
-# This script is intended to be a convenience, to be called from the
-# Makefile `.install.swagger` target.  Any other usage is not recommended.
-
-BIN="$BINDIR/swagger"
-
-die() { echo "${1:-No error message given} (from $(basename $0))"; exit 1; }
-
-function install() {
-    echo "Installing swagger v$VERSION into $BIN"
-    curl -sS --retry 5 --location -o $BIN \
-        https://github.com/go-swagger/go-swagger/releases/download/v$VERSION/swagger_${GOOS}_${GOARCH}
-    chmod +x $BIN
-    $BIN version
-}
-
-for req_var in VERSION BINDIR GOOS GOARCH; do
-    [[ -n "${!req_var}" ]] || die "\$$req_var is empty or undefined"
-done
-
-if [ ! -x "$BIN" ]; then
-    install
-else
-    $BIN version | grep "$VERSION"
-    if [[ "$?" -eq 0 ]]; then
-        echo "Using existing $BIN"
-    else
-        install
-    fi
-fi