protected final boolean hasConfigFile() {
        return hasConfigFile(configLocation());
    }
Returns {@code true} if the default configuration file is non-null,
exists and is readable. If, not, {@code false} is returned and an
appropriate message is shown in the console.

@return {@code true} if available, else {@code false}
build-parent/maven-plugin/src/main/java/com/speedment/maven/abstractmojo/AbstractSpeedmentMojo.java