Add `concat` to fp mapping.
Add `concat` to fp mapping.

beaugunderson/lodash,boneskull/lodash,tonyonodi/lodash,steelsojka/lodash,msmorgan/lodash,beaugunderson/lodash,rlugojr/lodash,msmorgan/lodash,boneskull/lodash,rlugojr/lodash,tonyonodi/lodash,steelsojka/lodash