Merge pull request #64 from Shopify/ap.commit-cargo-lock

Commit `Cargo.lock`

Author: adampetro

.gitignore

@@ -5,9 +5,5 @@
 # will have compiled files and executables
 /target/
 
-# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
-# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
-Cargo.lock
-
 # These are backup files generated by rustfmt
 **/*.rs.bk