Auto merge of #566 - Mark-Simulacrum:dep-prune, r=pietroalbini

Remove unused dependencies

Do some trivial cleanup of completely unused dependencies.

Author: bors

Cargo.lock

@@ -21,7 +21,6 @@ crates-index = "0.16.2"
 crossbeam-utils = "0.5"
 csv = "1.0.2"
 dotenv = "0.13"
-error-chain = "0.12"
 failure = "0.1.3"
 flate2 = "1"
 futures = "0.1.13"
@@ -41,7 +40,6 @@ rusoto_core = "0.35.0"
 rusoto_credential = "0.14.0"
 rusoto_s3 = "0.35.0"
 rusqlite = { version = "0.15.0", features = ["chrono", "functions", "bundled"] }
-scopeguard = "0.3"
 serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
@@ -52,7 +50,6 @@ tar = "0.4.0"
 tempfile = "3.0.0"
 tera = "0.11.7"
 tokio = "0.1.11"
-tokio-process = "0.2.3"
 toml = "0.4.6"
 url = "1.1"
 walkdir = "2"