Rename bazel-zig-cc to hermetic_cc_toolchain (#36)

As it says on the tin.

Long live hermetic_cc_toolchain!

test/gorace/BUILD

@@ -9,7 +9,7 @@ go_library(
     srcs = ["main.go"],
     # keep
     cgo = True,
-    importpath = "github.com/uber/bazel-zig-cc/test/gorace",
+    importpath = "github.com/uber/hermetic_cc_toolchain/test/gorace",
     visibility = ["//visibility:private"],
 )
 

test/gorace/main.go

@@ -9,7 +9,7 @@
 // More context: https://github.com/ziglang/zig/issues/11398
 //
 // This fails, because `zig cc` adds `--gc-sections` to the linker
-// flag by default, which is incompatible with cgo. bazel-zig-cc
+// flag by default, which is incompatible with cgo. hermetic_cc_toolchain
 // adds a workaround for it.
 package main