Bundle and use Inconsolata v2.012

There's a newer version of the font available but ligatures seem
broken googlefonts/Inconsolata#58 and googlefonts/Inconsolata#52.

As part of this commit I also upgraded rust-embed to use the new
exclusion feature, which allows us to skip embedding OS files like
`.DS_Store`.

server/Cargo.toml

@@ -29,7 +29,7 @@ oauth2-surf = "0.1.1"
 parking_lot = "0.11.1"
 postage = { version = "0.4.1", features = ["futures-traits"] }
 rand = "0.8"
-rust-embed = "5.9.0"
+rust-embed = { version = "6.2", features = ["include-exclude"] }
 scrypt = "0.7"
 serde = { version = "1.0", features = ["derive"] }
 sha-1 = "0.9"