tests: move/rename/cleanup vspec based tests (#860)

The main motivation is to being able to use normal/other pytest based
tests.

Therefore this moves everything from conftest into test_integration
itself.

test/vspec/completions_disabled.vim

@@ -0,0 +1,20 @@
+let g:jedi#completions_command = 'X'
+let g:jedi#completions_enabled = 0
+source plugin/jedi.vim
+
+describe 'completions_disabled'
+    before
+        set filetype=python
+    end
+
+    after
+        try | %bwipeout! | catch | endtry
+    end
+
+    it 'typing'
+        normal oraise ImportErrX
+        Expect getline('.') == 'raise ImportErrX'
+    end
+end
+
+" vim: et:ts=4:sw=4