add missing bc on travis
diff --git a/.travis.yml b/.travis.yml
index b8b80ad..6a0593e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -31,7 +31,7 @@
- export NUM_CPU="`grep processor /proc/cpuinfo | wc -l`"; echo $NUM_CPU
- sudo apt-get update -qq
# - sudo DEBIAN_FRONTEND=noninteractive apt-get -qq -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" upgrade
- - sudo apt-get install -qq libboost-dev libboost-test-dev libboost-program-options-dev libevent-dev automake libtool flex bison pkg-config g++ libssl-dev
+ - sudo apt-get install -qq libboost-dev libboost-test-dev libboost-program-options-dev libevent-dev automake libtool flex bison pkg-config g++ libssl-dev bc
# Java
- sudo apt-get install -qq ant
# Ruby