Allow skip-tls-verify option for testing

plugin.sh

@@ -28,11 +28,16 @@ fi
 DOCKERFILE=${PLUGIN_DOCKERFILE:-Dockerfile}
 CONTEXT=${PLUGIN_CONTEXT:-$PWD}
 LOG=${PLUGIN_LOG:-info}
+EXTRA_OPTS=""
 
 if [[ -n "${PLUGIN_TARGET:-}" ]]; then
     TARGET="--target=${PLUGIN_TARGET}"
 fi
 
+if [[ "${PLUGIN_SKIP_TLS_VERIFY:-}" == "true" ]]; then
+    EXTRA_OPTS="--skip-tls-verify=true"
+fi
+
 if [[ "${PLUGIN_CACHE:-}" == "true" ]]; then
     CACHE="--cache=true"
 fi
@@ -54,6 +59,7 @@ fi
 /kaniko/executor -v ${LOG} \
     --context=${CONTEXT} \
     --dockerfile=${DOCKERFILE} \
+    ${EXTRA_OPTS} \
     ${DESTINATIONS} \
     ${CACHE:-} \
     ${TARGET:-} \