Migrate all advisories to V2 format (closes #228)

As announced in #228, this commit migrates all advisories to the new V2
format, which splits version information into a separate section, and
now has a structure which corresponds to the internal code structure of
the `rustsec` crate.

This is a breaking change for users of `cargo-audit` < 0.9, and anyone
who has written a 3rd party advisory format parser.

crates/slice-deque/RUSTSEC-2018-0008.toml

@@ -2,7 +2,6 @@
 id = "RUSTSEC-2018-0008"
 package = "slice-deque"
 date = "2018-12-05"
-patched_versions = [">= 0.1.16"]
 url = "https://github.com/gnzlbg/slice_deque/issues/57"
 keywords = ["memory-corruption", "rce"]
 title = "Bug in SliceDeque::move_head_unchecked allows read of corrupted memory"
@@ -23,3 +22,6 @@ alter program execution.
 
 The flaw was corrected by properly updating the head and tail of the deque in
 this case. """
+
+[versions]
+patched = [">= 0.1.16"]

crates/slice-deque/RUSTSEC-2019-0002.toml

@@ -3,12 +3,10 @@ id = "RUSTSEC-2019-0002"
 package = "slice-deque"
 date = "2019-05-07"
 title = "Bug in SliceDeque::move_head_unchecked corrupts its memory"
-patched_versions = [">= 0.2.0"]
 url = "https://github.com/gnzlbg/slice_deque/issues/57"
 keywords = ["memory-corruption", "rce"]
 references = ["RUSTSEC-2018-0008"]
 description = """
-
 Affected versions of this crate entered a corrupted state if
 `mem::size_of::<T>() % allocation_granularity() != 0` and a specific allocation
 pattern was used: sufficiently shifting the deque elements over the mirrored
@@ -22,4 +20,8 @@ whose value representation is not meaningful). This is undefined behavior.
  
 The flaw was corrected by using a pair of pointers to track the head and tail of
 the deque instead of a pair of indices. This pair of pointers are represented
-using a Rust slice."""
+using a Rust slice.
+"""
+
+[versions]
+patched = [">= 0.2.0"]