Adding manticore (#226)

Author: feliam

_sections/30-projects.md

@@ -80,6 +80,7 @@ These projects pledge to drop Python 2 support in or before 2020.
 - [![](assets/freud.png)freud](https://github.com/glotzerlab/freud)
 - [![](assets/signac.png)signac](https://signac.io)
 - [![](assets/platon.png)PLATON](https://github.com/ideasrule/platon)
+- [![](assets/manticore.png)Manticore](https://github.com/trailofbits/manticore)
 
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