[xc7] Docker's torc not to make install

.cirrus/Dockerfile.ubuntu16.04

diff --git a/.cirrus/Dockerfile.ubuntu16.04 b/.cirrus/Dockerfile.ubuntu16.04
index 673fb54..cf665c5 100644
--- a/.cirrus/Dockerfile.ubuntu16.04
+++ b/.cirrus/Dockerfile.ubuntu16.04
@@ -58,5 +58,4 @@
     git clone --recursive https://github.com/eddiehung/torc.git ;\
     cd torc ;\
     git reset --hard 90874d1293fbeba77bae41b5c38168cd91e1bf00 ;\
-    make -j $(nproc) -C src/torc ;\
-    make install
+    make -j $(nproc) -C src/torc