Update Rust crate diesel_migrations to 1.4.0

Author: renovate-bot

Cargo.toml

@@ -52,7 +52,7 @@ derive_deref = "1.1.1"
 dialoguer = "0.9"
 diesel = { version = "1.4.8", features = ["postgres", "serde_json", "chrono", "r2d2"] }
 diesel_full_text_search = "1.0.0"
-diesel_migrations = { version = "1.3.0", features = ["postgres"] }
+diesel_migrations = { version = "1.4.0", features = ["postgres"] }
 dotenv = "0.15"
 flate2 = "1.0"
 futures-channel = { version = "0.3.1", default-features = false }
@@ -98,5 +98,5 @@ tower-service = "0.3.0"
 
 [build-dependencies]
 diesel = { version = "1.4.8", features = ["postgres"] }
-diesel_migrations = { version = "1.3.0", features = ["postgres"] }
+diesel_migrations = { version = "1.4.0", features = ["postgres"] }
 dotenv = "0.15"