Adding Accumulo 1.7.4 checksum (#175)

diff --git a/conf/checksums b/conf/checksums
index f20ac22..e491a60 100644
--- a/conf/checksums
+++ b/conf/checksums
@@ -1,4 +1,5 @@
 accumulo:1.8.1:eba3bfe823935ca7901ea7c2bd59c84a68b9381361699c7e260bbd9191f237f4
+accumulo:1.7.4:3776dddbc2a09f4a9d7a2ae4958e212e91eb5067a124a628330edbee4e32e754
 accumulo:1.7.3:294f2f1f3fbc164b68e80cecd5a6ce5c245df804fb35ae5e03ab1c86bc9480da
 hadoop:2.9.0:8d48666f29f9ade6ed2762b7a9edab177bad2c57396f43d0ffd6a269d54f6fe1
 hadoop:2.8.3:e8bf9a53337b1dca3b152b0a5b5e277dc734e76520543e525c301a050bb27eae