Loggregator 70

Note: This version of Loggregator restricts ciphers to use only the following 4 ciphers. This is a breaking change for some operators and a configurable property for opting into more cipher suites was introduced in Loggregator 85
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

• Updated to golang 1.7.4
• Updated ciphers suites to more secure ciphers.