Can the maintainer provide a clang-format file for better code consistency?

I have found that there are several different coding styles in gtsam's repo at present. Can we provide a clang-format file to ensure the consistency of the code format? Such as 

.clang-format
```
BasedOnStyle: Google

BinPackArguments: false
BinPackParameters: false
ColumnLimit: 100
DerivePointerAlignment: false
IncludeBlocks: Preserve
PointerAlignment: Left
```
