[travis] add --test-verilog tests to build matrix
[travis] add --test-verilog tests to build matrix

Glyfina-Fernando/pymtl,jck/pymtl,12yujim/pymtl,jck/pymtl,cfelton/pymtl,cfelton/pymtl,jjffryan/pymtl,tj93/pymtl,jck/pymtl,jjffryan/pymtl,tj93/pymtl,cornell-brg/pymtl,cornell-brg/pymtl,cornell-brg/pymtl,Glyfina-Fernando/pymtl,Glyfina-Fernando/pymtl,12yujim/pymtl,cfelton/pymtl,tj93/pymtl,jjffryan/pymtl,12yujim/pymtl