Use the same compiler for c

.travis.yml

@@ -13,7 +13,9 @@ matrix:
         - os: linux
           compiler: gcc
           env:
-            - COMPILER=g++-6
+            - CXX_COMPILER=g++-6
+            - C_COMPILER=gcc-6
+            - DEPLOYMENT=1
           addons:
             apt:
               sources: ['ubuntu-toolchain-r-test']
@@ -21,14 +23,16 @@ matrix:
         - os: linux
           compiler: clang
           env:
-            - COMPILER=clang++-5.0
+            - CXX_COMPILER=clang++-5.0
+            - C_COMPILER=clang-5.0
           addons:
             apt:
               sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-trusty-5.0']
               packages: ['clang-5.0']
 
 before_install:
-    - export CXX=${COMPILER}
+    - export CXX=${CXX_COMPILER}
+    - export CC=${C_COMPILER}
 
 install:
     - if [ $TRAVIS_OS_NAME == osx ]; then brew update && brew install qt5 lmdb clang-format; fi
@@ -53,7 +57,7 @@ deploy:
           secure: 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
       file: nheko-x86_64.AppImage
       on:
-          condition: $TRAVIS_OS_NAME == linux
+          condition: $TRAVIS_OS_NAME == linux && $DEPLOYMENT == 1
           repo: mujx/nheko
           tags: true
     - skip_cleanup: true