Travis: remove redundant builds

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

.travis.yml

@@ -7,55 +7,6 @@ matrix:
       osx_image: xcode9.3
       language: c++
 
-    - env: SUBSURFACE_PLATFORM='windows-container'
-      os: linux
-      filter_secrets: false
-      language: c++
-      services:
-          - docker
-
-    - env: SUBSURFACE_PLATFORM='linux'
-      os: linux
-      dist: trusty
-      language: c++
-      addons:
-        apt:
-          packages:
-            - git
-            - g++
-            - make
-            - autoconf
-            - automake
-            - libtool
-            - cmake
-            - pkg-config
-            - libxml2-dev
-            - libxslt1-dev
-            - libzip-dev
-            - libsqlite3-dev
-            - libusb-1.0-0-dev
-            - libssl-dev
-            - libssh2-1-dev
-            - libcurl4-openssl-dev
-            # Not a subsurface dependency, but a Qt dependency
-            - mesa-common-dev
-            - libqt5gui5
-            - libxcb-xinerama0
-            # Not a subsurface dependency, but a QtMultimedia/libdeclarative_multimedia.so dependency
-            - libpulse-mainloop-glib0
-            # Not a subsurface dependency, but a QtWebKit dependency
-            - libhyphen-dev
-            - libicu52
-            # For SmartTrak import
-            - libglib2.0-dev
-            - mdbtools-dev
-
-    - env: SUBSURFACE_PLATFORM='linux-trusty-qt512'
-      os: linux
-      language: c++
-      services:
-          - docker
-
     - env: SUBSURFACE_PLATFORM="android"
       # Currently hard coded to arm
       os: linux
@@ -63,18 +14,6 @@ matrix:
       filter_secrets: false
       services:
           - docker
-# TODO: caching
-#      cache:
-#          timeout: 300
-#          directories:
-#              - 3pp
-
-    - env: SUBSURFACE_PLATFORM="qt59"
-      os: linux
-      language: c++
-      filter_secrets: false
-      services:
-          - docker
 
 before_install:
     - source ${TRAVIS_BUILD_DIR}/scripts/${SUBSURFACE_PLATFORM}/before_install.sh