Vendor dependencies

Let's see how I like this workflow.

vendor/pathdiff/Cargo.toml

@@ -0,0 +1,26 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+name = "pathdiff"
+version = "0.2.1"
+authors = ["Manish Goregaokar <manishsmail@gmail.com>"]
+description = "Library for diffing paths to obtain relative paths"
+documentation = "https://docs.rs/pathdiff/"
+keywords = ["path", "relative"]
+license = "MIT/Apache-2.0"
+repository = "https://github.com/Manishearth/pathdiff"
+[package.metadata.docs.rs]
+all-features = true
+[dependencies.camino]
+version = "1.0.5"
+optional = true