Update to Embark standard lints v0.4

Following EmbarkStudios/rust-ecosystem#66,
tame-oauth also needed to update.

src/lib.rs

@@ -1,25 +1,36 @@
-// BEGIN - Embark standard lints v0.3
+// BEGIN - Embark standard lints v0.4
 // do not change or add/remove here, but one can add exceptions after this section
 // for more info see: <https://github.com/EmbarkStudios/rust-ecosystem/issues/59>
+#![deny(unsafe_code)]
 #![warn(
     clippy::all,
     clippy::await_holding_lock,
+    clippy::char_lit_as_u8,
+    clippy::checked_conversions,
     clippy::dbg_macro,
     clippy::debug_assert_with_mut_call,
     clippy::doc_markdown,
     clippy::empty_enum,
+    clippy::enum_glob_use,
     clippy::exit,
+    clippy::expl_impl_clone_on_copy,
+    clippy::explicit_deref_methods,
     clippy::explicit_into_iter_loop,
+    clippy::fallible_impl_from,
     clippy::filter_map_next,
+    clippy::float_cmp_const,
     clippy::fn_params_excessive_bools,
     clippy::if_let_mutex,
+    clippy::implicit_clone,
     clippy::imprecise_flops,
     clippy::inefficient_to_string,
+    clippy::invalid_upcast_comparisons,
     clippy::large_types_passed_by_value,
     clippy::let_unit_value,
     clippy::linkedlist,
     clippy::lossy_float_literal,
     clippy::macro_use_imports,
+    clippy::manual_ok_or,
     clippy::map_err_ignore,
     clippy::map_flatten,
     clippy::map_unwrap_or,
@@ -28,28 +39,36 @@
     clippy::match_wildcard_for_single_variants,
     clippy::mem_forget,
     clippy::mismatched_target_os,
+    clippy::mut_mut,
+    clippy::mutex_integer,
     clippy::needless_borrow,
     clippy::needless_continue,
     clippy::option_option,
-    clippy::pub_enum_variant_names,
+    clippy::path_buf_push_overwrite,
+    clippy::ptr_as_ptr,
     clippy::ref_option_ref,
     clippy::rest_pat_in_fully_bound_structs,
+    clippy::same_functions_in_if_condition,
+    clippy::semicolon_if_nothing_returned,
     clippy::string_add_assign,
     clippy::string_add,
+    clippy::string_lit_as_bytes,
     clippy::string_to_string,
-    clippy::suboptimal_flops,
     clippy::todo,
-    clippy::enum_glob_use,
+    clippy::trait_duplication_in_bounds,
     clippy::unimplemented,
     clippy::unnested_or_patterns,
     clippy::unused_self,
+    clippy::useless_transmute,
     clippy::verbose_file_reads,
+    clippy::zero_sized_map_values,
     future_incompatible,
     nonstandard_style,
     rust_2018_idioms
 )]
-// END - Embark standard lints v0.3
+// END - Embark standard lints v0.4
 // crate-specific exceptions:
+#![allow()]
 
 //! # 🔐 tame-oauth
 //!