diff --git a/Cargo.lock b/Cargo.lock
index 5afbdfa63..a22e1e110 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -305,6 +305,7 @@ dependencies = [
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.11.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "md5 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "r2d2 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "reqwest 0.8.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -895,6 +896,11 @@ name = "matches"
 version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "md5"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "memchr"
 version = "2.0.1"
@@ -2190,6 +2196,7 @@ dependencies = [
 "checksum log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "89f010e843f2b1a31dbd316b3b8d443758bc634bed37aabade59c686d644e0a2"
 "checksum lru-cache 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4d06ff7ff06f729ce5f4e227876cb88d10bc59cd4ae1e09fbb2bde15c850dc21"
 "checksum matches 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "100aabe6b8ff4e4a7e32c1c13523379802df0772b82466207ac25b013f193376"
+"checksum md5 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)" = "daa1004633f76cdcd5a9d83ffcfe615e30ca7a2a638fcc8b8039a2dac21289d7"
 "checksum memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "796fba70e76612589ed2ce7f45282f5af869e0fdd7cc6199fa1aa1f1d591ba9d"
 "checksum memoffset 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e163e5baece1a039e71e75b074de17a9b4114982aa109921fc20253bdf91a53c"
 "checksum memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0f9dc261e2b62d7a622bf416ea3c5245cdd5d9a7fcc428c0d06804dfce1775b3"
diff --git a/Cargo.toml b/Cargo.toml
index 284e0a702..45c3215c3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,3 +24,4 @@ serde_json = "1.0"
 hyper = "0.11"
 rand = "0.4"
 comrak = "0.2"
+md5 = "0.3.7"
diff --git a/src/main.rs b/src/main.rs
index 434bd40f3..a3ad36430 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -16,9 +16,11 @@ extern crate failure;
 extern crate actix;
 extern crate actix_web;
 extern crate chrono;
+extern crate comrak;
 extern crate env_logger;
 extern crate futures;
 extern crate hyper;
+extern crate md5;
 extern crate r2d2;
 extern crate rand;
 extern crate reqwest;