Adding caching support in travis-ci builds

.travis.yml

@@ -24,3 +24,9 @@ env:
 
 install: ./.travis/install.sh
 script:  ./.travis/run.sh
+
+cache:
+    ccache: true
+    directories:
+    - conan         # Conan installation folder
+    - $HOME/.conan  # Conan configuration and packages

.travis/install.sh

@@ -4,7 +4,7 @@ set -x
 
 if [[ "$(uname -s)" == 'Linux' ]]; then
     sudo apt-get install cmake zlib1g-dev libssh-dev libcurl4-openssl-dev gettext libexpat1-dev
-    sudo apt-get install python-pip
+    sudo apt-get install python-pip libxml2-utils
     sudo pip install virtualenv
 else
     brew update

.travis/run.sh

@@ -6,8 +6,7 @@ set -x
 source conan/bin/activate
 mkdir build && cd build
 conan install .. --build missing --profile release
-cmake ${CMAKE_OPTIONS} ..
-cmake -DCMAKE_INSTALL_PREFIX=install ..
+cmake ${CMAKE_OPTIONS} -DCMAKE_INSTALL_PREFIX=install ..
 make -j
 make tests
 make install