Fixing crash on large result

- Added depencency bignum
- Using num::BigNum in format::pprint to handle f64 numbers that are
larger than maximal i64 number (which was causing the bug)

If you want full feature parity with bc perhaps bignums can be used as
long as all operations are done on integers.

1 files changed, 1 insertions, 0 deletions

diff --git a/Cargo.toml b/Cargo.toml
index d1cf3be..72be383 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,3 +18,4 @@ radix_fmt   = "1.0.0"
 lazy_static = "1.3.0"
 directories = "2.0.1"
 regex       = "1.1.7"
+num         = "0.2"