Updated readme for 2.1.5

[maven-release-plugin] copy for tag browsermob-proxy-2.1.5

[maven-release-plugin] copy for tag browsermob-proxy-2.1.4

[maven-release-plugin] copy for tag browsermob-proxy-2.1.3

[maven-release-plugin] copy for tag browsermob-proxy-2.1.2

[maven-release-plugin] copy for tag browsermob-proxy-2.1.1

[maven-release-plugin] copy for tag browsermob-proxy-2.1.0

[maven-release-plugin] copy for tag browsermob-proxy-2.1.0-beta-6

[maven-release-plugin] copy for tag browsermob-proxy-2.1.0-beta-5

[maven-release-plugin] copy for tag browsermob-proxy-2.1.0-beta-4