Fix travis tests

Author: isuruf

.travis.yml

@@ -53,17 +53,20 @@ matrix:
           packages:
           - binutils-dev
           - g++-4.8
-    - env: BUILD_TYPE="Debug" WITH_BFD="yes" PYTHON_VERSION="3.5" WITH_LLVM="3.8" WITH_SCIPY="yes" BUILD_SHARED_LIBS="yes"
+    - env: BUILD_TYPE="Debug" WITH_BFD="yes" PYTHON_VERSION="3.5" WITH_LLVM="7.0" WITH_SCIPY="yes" BUILD_SHARED_LIBS="yes"
       compiler: clang
       os: linux
       addons:
         apt:
           sources:
           - ubuntu-toolchain-r-test
+          - llvm-toolchain-trusty-7
           packages:
           - clang
           - libstdc++-4.8-dev
           - binutils-dev
+          - clang-7
+          - llvm-7-dev
     - env: BUILD_TYPE="Release" PYTHON_VERSION="2.7" WITH_NUMPY="no"
       compiler: clang
       os: linux

bin/install_travis.sh

@@ -1,7 +1,6 @@
 #!/usr/bin/env bash
 
 # symengine's bin/install_travis.sh will install miniconda
-conda update -q -n root conda
 
 export conda_pkgs="python=${PYTHON_VERSION} pip cython nose pytest"