Invalid value generated for graph bb field

[brianpartridge]

Describe the bug
ruby-graphviz seems to generate invalid dot formatted numbers for bounding boxes of 6 digits or more. This may be an issue with how all numbers get formatted across all dot output.

Detailed Background
In the cocoapods-dependencies plugin we use ruby-graphviz to output a module dependency graph like so. In my very large project that I'm using this plugin with, the output contains dot file contains graph [bb="0,0,1.0029e+05,1620"];. Later, I send this dot file through gvpr and another script using ruby-graphviz, but when I do so I get the following error:
Invalid value 0,0,1.0029e+05,1620for attributebb : Invalid rect value

To Reproduce
See detailed background above, I don't have a sharable reproduction case, but it seems to happen in graphs with 100s of nodes and thousands of edges.

Expected behavior
Output dot file should contain numbers that aren't formatted in scientific notation. Ex graph [bb="0,0,100290,1620"];

Environment (please complete the following information):

• OS: macOS
• Version 11.2.1
• Ruby 2.6.1
• Ruby Manager rvm
• Ruby Manager Version 1.29.10