install_rote.sh: set prefix with ./configure

See discussion here: http://habrahabr.ru/post/254089/#comment_8349843

Changing prefix in Makefile (or with make command line arguments) doesn't
change it in rote-config, other file generated by ./configure

Providing prefix to ./configure is more reliable.

.travis/install_rote.sh

@@ -3,9 +3,9 @@ sudo apt-get install libncurses5-dev
 wget http://sourceforge.net/projects/rote/files/rote/rote-0.2.8/rote-0.2.8.tar.gz
 tar -xf rote-0.2.8.tar.gz
 cd rote-0.2.8/
-./configure
+./configure --prefix=/usr
 make
-sudo make install prefix=/usr
+sudo make install
 
 cd ..
 sudo rm -rf rote-0.2.8/