Adds more tests, including failure cases
Adds more tests, including failure cases

rust-num/num-integer,rust-num/num-bigint,rust-lang/num,koverstreet/num,rust-num/num,rust-num/num-bigint,rust-num/num-integer,rust-num/num,rust-num/num-traits,rust-num/num-traits,rust-lang/num,koverstreet/num