Update petgraph dependency to 0.4.13

This fixes building `bootstrap` using a local Rust nightly.

Author: GabrielMajeri

src/Cargo.lock

@@ -138,7 +138,7 @@ dependencies = [
  "lazy_static 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "petgraph 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "petgraph 0.4.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.75 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.75 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1471,7 +1471,7 @@ dependencies = [
 
 [[package]]
 name = "petgraph"
-version = "0.4.12"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "fixedbitset 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3243,7 +3243,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum percent-encoding 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "31010dd2e1ac33d5b46a5b413495239882813e0369f8ed8a5e266f173602f831"
 "checksum pest 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0fce5d8b5cc33983fc74f78ad552b5522ab41442c4ca91606e4236eb4b5ceefc"
 "checksum pest_derive 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)" = "ab94faafeb93f4c5e3ce81ca0e5a779529a602ad5d09ae6d21996bfb8b6a52bf"
-"checksum petgraph 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "8b30dc85588cd02b9b76f5e386535db546d21dc68506cff2abebee0b6445e8e4"
+"checksum petgraph 0.4.13 (registry+https://github.com/rust-lang/crates.io-index)" = "9c3659d1ee90221741f65dd128d9998311b0e40c5d3c23a62445938214abce4f"
 "checksum phf 0.7.22 (registry+https://github.com/rust-lang/crates.io-index)" = "7d37a244c75a9748e049225155f56dbcb98fe71b192fd25fd23cb914b5ad62f2"
 "checksum phf_codegen 0.7.22 (registry+https://github.com/rust-lang/crates.io-index)" = "4e4048fe7dd7a06b8127ecd6d3803149126e9b33c7558879846da3a63f734f2b"
 "checksum phf_generator 0.7.22 (registry+https://github.com/rust-lang/crates.io-index)" = "05a079dd052e7b674d21cb31cbb6c05efd56a2cd2827db7692e2f1a507ebd998"

src/bootstrap/Cargo.toml

@@ -47,7 +47,7 @@ serde_json = "1.0.2"
 toml = "0.4"
 lazy_static = "0.2"
 time = "0.1"
-petgraph = "0.4.12"
+petgraph = "0.4.13"
 
 [dev-dependencies]
 pretty_assertions = "0.5"