Add travis gcc-multilib package

Jan Breuer

2015-10-04 f32fd36dc6a6a41e4a70d021096f2f7c53490c5d

 libscpi/inc/scpi/types.h

@@ -142,6 +142,7 @@
        SCPI_TOKEN_COMMA,
        SCPI_TOKEN_SEMICOLON,
        SCPI_TOKEN_COLON,
        SCPI_TOKEN_SPECIFIC_CHARACTER,
        SCPI_TOKEN_QUESTION,
        SCPI_TOKEN_NL,
        SCPI_TOKEN_HEXNUM,