Move backend checks to build.rs to fail fast, and updated dependencies

Cargo.toml

@@ -40,9 +40,9 @@ rmpv = "0.4.0"
 chashmap = "2.2.2"
 
 # A generic serialization/deserialization framework
-serde = "1.0.92"
-serde_derive = "1.0.92"
-serde_json = "1.0.39"
+serde = "1.0.94"
+serde_derive = "1.0.94"
+serde_json = "1.0.40"
 
 # Logging
 log = "0.4.6"
@@ -62,7 +62,7 @@ ring = "0.14.6"
 uuid = { version = "0.7.4", features = ["v4"] }
 
 # Date and time library for Rust
-chrono = "0.4.6"
+chrono = "0.4.7"
 
 # TOTP library
 oath = "0.10.2"
@@ -77,7 +77,7 @@ jsonwebtoken = "6.0.1"
 u2f = "0.1.6"
 
 # Yubico Library
-yubico = { version = "0.5.1", features = ["online"], default-features = false }
+yubico = { version = "0.6.1", features = ["online", "online-tokio"], default-features = false }
 
 # A `dotenv` implementation for Rust
 dotenv = { version = "0.14.1", default-features = false }
@@ -99,11 +99,11 @@ native-tls = "0.2.3"
 quoted_printable = "0.4.1"
 
 # Template library
-handlebars = "1.1.0"
+handlebars = "2.0.0"
 
 # For favicon extraction from main website
 soup = "0.4.1"
-regex = "1.1.7"
+regex = "1.1.9"
 
 # URL encoding library
 percent-encoding = "1.0.1"