RUST-346 Implement bson corpus spec tests (#166)

Author: saghm

Cargo.toml

@@ -35,11 +35,13 @@ linked-hash-map = "0.5"
 hex = "0.3"
 md5 = "0.6"
 decimal = { version = "2.0.4", default_features = false, optional = true }
+base64 = "0.12.1"
 
 [dev-dependencies]
 assert_matches = "1.2"
 serde_derive = "1.0"
 serde_bytes = "0.11"
+pretty_assertions = "0.6.1"
 
 [package.metadata.docs.rs]
 features = ["decimal128"]