tests: drop Go 1.3.3 from Travis testing

Does not support testing.M, which means we cannot run the
test suite, which means we cannot claim to support it at
all.

.travis.yml

@@ -3,7 +3,6 @@ language: go
 # Debian Jessie has Go 1.3.3, Fedora 22 has Go 1.4.3,
 # Fedora 23 has Go 1.5.1
 go:
-  - 1.3.3
   - 1.4.3
   - 1.5.1
   - 1.6
@@ -12,12 +11,11 @@ go:
 install:
   - go get .
 
-# Go 1.3.3 does not support testing.M, so skip the tests there.
 script:
   - openssl version
   - go build
   - ./build.bash
-  - if ! go version | grep go1.3.3 ; then ./test.bash ; fi
+  - ./test.bash
 
 # fuse on travis
 sudo: required