CI: Assure tmux version in PATH

Author: tony

.github/workflows/libtmux-ci.yml

@@ -30,7 +30,7 @@ jobs:
         git checkout ${{ matrix.tmux-version }}
         sh autogen.sh
         ./configure --prefix=$HOME/tmux-builds/tmux-${{ matrix.tmux-version }} && make && make install
-        export PATH=$PATH:$HOME/tmux-builds/tmux-${{ matrix.tmux-version }}/bin
+        export PATH=$HOME/tmux-builds/tmux-${{ matrix.tmux-version }}/bin:$PATH
         cd ~
         tmux -V
     - name: Configure git
@@ -50,6 +50,8 @@ jobs:
         pipenv run flake8
     - name: Test with pytest
       run: |
+        export PATH=$HOME/tmux-builds/tmux-${{ matrix.tmux-version }}/bin:$PATH
+        ls $HOME/tmux-builds/tmux-${{ matrix.tmux-version }}/bin
         tmux -V
         pipenv run py.test --cov=./ --cov-report=xml
     - uses: codecov/codecov-action@v1