Add YAML as a config format option

@mustafa89 ;)

Cargo.lock

@@ -195,6 +195,7 @@ dependencies = [
  "git2",
  "regex",
  "serde",
+ "serde_yaml",
  "shellexpand",
  "tempdir",
  "toml",
@@ -336,6 +337,12 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "linked-hash-map"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fb9b38af92608140b86b693604b9ffcc5824240a484d1ecd4795bacb2fe88f3"
+
 [[package]]
 name = "lock_api"
 version = "0.4.5"
@@ -592,6 +599,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "ryu"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73b4b750c782965c211b42f022f59af1fbceabdd026623714f104152f1ec149f"
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
@@ -618,6 +631,18 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "serde_yaml"
+version = "0.8.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4a521f2940385c165a24ee286aa8599633d162077a54bdcae2a6fd5a7bfa7a0"
+dependencies = [
+ "indexmap",
+ "ryu",
+ "serde",
+ "yaml-rust",
+]
+
 [[package]]
 name = "shellexpand"
 version = "2.1.0"
@@ -850,3 +875,12 @@ name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
+[[package]]
+name = "yaml-rust"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56c1936c4cc7a1c9ab21a1ebb602eb942ba868cbd44a99cb7cdc5892335e1c85"
+dependencies = [
+ "linked-hash-map",
+]