set bundled package paths in plan

There is a key difference between Fedora and RHEL. Fedora has pcs as a
noarch package which causes it to be installed into /usr/lib rather
than /usr/lib64. This means that bundled packages have a different path.
This caused import errors in tests.

There is also a better way of setting the environment variables -
through tmt instead of the preparation script.

plan-gating.fmf

@@ -1,6 +1,11 @@
 summary: PCS gating test plan
 description: Runs upstream tier0, tier1 and smoke tests
 
+# Always use bundled packages from system
+environment:
+    PYTHONPATH: /usr/lib64/pcs/pcs_bundled/packages/
+    GEM_HOME: /usr/lib64/pcsd/vendor/bundle/
+
 discover:
     dist-git-source: true
     dist-git-install-builddeps: true

tests/prepare-tests.sh

@@ -12,9 +12,6 @@ rm -rfv *SPECPARTS
 # Remove pcs-web-ui, pcs-*-build for "cd pcs-*" to have exactly one match
 rm -rf pcs-web-ui-* pcs-*-build
 cd pcs-*/
-# Run autotools, use bundled dependencies from the system
-export PYTHONPATH=/usr/lib/pcs/pcs_bundled/packages/
-export GEM_HOME=/usr/lib/pcsd/vendor/bundle/
 ./autogen.sh
 ./configure --enable-local-build --enable-use-local-cache-only \
   --enable-individual-bundling --enable-webui --with-pcs-lib-dir=/usr/lib