fix error in piece table tests; try install later version of sdl2

.travis.yml

@@ -7,4 +7,9 @@ sudo: required
 before_install:
   - sudo apt-get update -qq
   - sudo apt-get install libegl1-mesa-dev libgles2-mesa-dev
-  - sudo apt-get install libsdl2-dev libsdl2-image-dev libsdl2-ttf-dev xclip
+  travis_retry curl -L https://www.libsdl.org/release/SDL2-2.0.8.tar.gz | tar xz
+  cd SDL2-2.0.8
+  ./configure
+  make
+  sudo make install
+  - sudo apt-get install libsdl2-image-dev libsdl2-ttf-dev xclip

piecetable/piecetable_test.go

@@ -34,7 +34,7 @@ func TestBadRedo(t *testing.T) {
 document i want to see how it fares
 and all of that fun
 stuff`
-	output := `this is my piece foo table testing
+	output := `this is my piece table testing
 document i want to see how it fares
 and all of that fun
 stuff`