Fetching content from HTTPS using rustls (#2024)

* Fetching https

* Fetching dispatcher (HTTP, HTTPS)

* Fetching from github

* Chunked encoding parser

* Abort support

* Fixing tests and review comments

* Cargo.lock order [ci skip]

* Relaxed -> SeqCst

util/src/sha3.rs

@@ -69,7 +69,7 @@ impl<T> Hashable for T where T: AsRef<[u8]> {
 }
 
 /// Calculate SHA3 of given stream.
-pub fn sha3<R: io::Read>(r: &mut R) -> Result<H256, io::Error> {
+pub fn sha3(r: &mut io::BufRead) -> Result<H256, io::Error> {
 	let mut output = [0u8; 32];
 	let mut input = [0u8; 1024];
 	let mut sha3 = Keccak::new_keccak256();
@@ -90,7 +90,7 @@ pub fn sha3<R: io::Read>(r: &mut R) -> Result<H256, io::Error> {
 #[cfg(test)]
 mod tests {
 	use std::fs;
-	use std::io::Write;
+	use std::io::{Write, BufReader};
 	use super::*;
 
 	#[test]
@@ -113,7 +113,7 @@ mod tests {
 			file.write_all(b"something").unwrap();
 		}
 
-		let mut file = fs::File::open(&path).unwrap();
+		let mut file = BufReader::new(fs::File::open(&path).unwrap());
 		// when
 		let hash = sha3(&mut file).unwrap();