Try to fix Dockerfile.

Dockerfile

@@ -47,6 +47,7 @@ RUN \
     #   Fiber.poolSize = 1e9;
     # Getting newest Node from Sandstorm fork of Node
     # Source: https://github.com/sandstorm-io/node
+    curl -sL https://deb.nodesource.com/setup_8.x | bash -
     wget https://raw.githubusercontent.com/wekan/wekan/devel/download-sandstorm-node.sh && \
     bash download-sandstorm-node.sh && \
     rm download-sandstorm-node.sh && \

download-sandstorm-node.sh

@@ -27,7 +27,6 @@ SIGNING_KEY_ID=160D2D577518B58D94C9800B63F227499DA8CCBD
 
 TARBALL=sandstorm-$SANDSTORM_LAST_BUILD.tar.xz
 NODE_EXE=sandstorm-$SANDSTORM_LAST_BUILD/bin/node
-NPM_EXE=sandstorm-$SANDSTORM_LAST_BUILD/bin/npm
 
 echo "=== DOWNLOADING SANDSTORM GPG KEYS TO VERIFY SANDSTORM RELEASE ==="
 
@@ -61,7 +60,7 @@ fi
 
 echo "=== EXTRACTING NODE FROM SANDSTORM RELEASE TARBALL ==="
 # --strip 2 removes path of 2 subdirectories
-tar -xf $TARBALL $NODE_EXE $NPM_EXE --strip=2
+tar -xf $TARBALL $NODE_EXE --strip=2
 
 echo "=== REMOVING SANDSTORM RELEASE TARBALL AND SIGNATURE ==="
 rm $TARBALL $TARBALL.sig release-certificate.kentonv.si*