refactor(lib): clean up unused dependencies

Cargo.toml

@@ -21,7 +21,6 @@ include = [
 ]
 
 [dependencies]
-base64 = "0.9"
 bytes = "0.4.4"
 futures = "0.1.17"
 futures-cpupool = "0.1.6"
@@ -29,18 +28,13 @@ futures-timer = "0.1.0"
 http = "0.1.5"
 httparse = "1.0"
 iovec = "0.1"
-language-tags = "0.2"
 log = "0.4"
-mime = "0.3.2"
 net2 = "0.2.32"
-percent-encoding = "1.0"
-relay = "0.1"
 time = "0.1"
 tokio = "0.1.3"
 tokio-executor = "0.1.0"
 tokio-service = "0.1"
 tokio-io = "0.1"
-unicase = "2.0"
 
 [dev-dependencies]
 num_cpus = "1.0"