Update base64 requirement from 0.13 to 0.21 (#33)

Updates the requirements on [base64](https://github.com/marshallpierce/rust-base64) to permit the latest version.
- [Release notes](https://github.com/marshallpierce/rust-base64/releases)
- [Changelog](https://github.com/marshallpierce/rust-base64/blob/master/RELEASE-NOTES.md)
- [Commits](marshallpierce/rust-base64@v0.13.0...v0.21.0)

---
updated-dependencies:
- dependency-name: base64
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Cargo.toml

@@ -16,7 +16,7 @@ rust-version = "1.64"
 version = "0.0.7-alpha"
 
 [dependencies]
-base64 = "0.13"
+base64 = "0.21"
 byteorder = "1.4"
 const-str = "0.5"
 serde = { version = "1.0", features = ["derive"] }

src/imp/http_proxy.rs

@@ -12,7 +12,7 @@ use serde_json::Deserializer;
 use crate::errors::{DecLibraryError, DecUseError};
 use crate::imp::content_type;
 use crate::imp::hyper_proxy::HyperHttpClient;
-use crate::imp::other::converge;
+use crate::imp::other::{base64_encode, converge};
 use crate::model::{RegistryAuth, RegistryConfig};
 use crate::responses::ErrorResponse;
 
@@ -140,7 +140,7 @@ impl DockerEngineHttpClient {
                 let json = serde_json::to_string(&auth)
                     .map_err(DecLibraryError::RegistryAuthJsonEncodingError)?;
 
-                Ok(Some(base64::encode(json)))
+                Ok(Some(base64_encode(json)))
             }
         }
     }
@@ -153,7 +153,7 @@ impl DockerEngineHttpClient {
             let json = serde_json::to_string(registry_config)
                 .map_err(DecLibraryError::RegistryAuthJsonEncodingError)?;
 
-            Ok(Some(base64::encode(json)))
+            Ok(Some(base64_encode(json)))
         }
     }
 }

src/imp/other.rs

@@ -1,4 +1,13 @@
 
+
+/// Convenience wrapper over base64 crate's breaking changes
+pub(crate) fn base64_encode<T: AsRef<[u8]>>(input: T) -> String {
+    use base64::engine::general_purpose::STANDARD;
+    use base64::Engine;
+
+    STANDARD.encode(input)
+}
+
 /// Some functions convert/extract input parameters that represent failure information.
 /// That information is converted to an error result type.
 ///
@@ -13,6 +22,20 @@ pub(crate) fn converge<A>(result: Result<A, A>) -> A {
     }
 }
 
+#[cfg(test)]
+mod test_base64_encode {
+    use super::base64_encode;
+
+    //noinspection SpellCheckingInspection
+    #[test]
+    fn encodes() {
+        let input: [u8; 4] = [2, 3, 4, 5];
+
+        let expected = "AgMEBQ==";
+        assert_eq!(expected, base64_encode(input));
+    }
+}
+
 #[cfg(test)]
 mod test_converge {
     use super::converge;