Update travis.yml

Julia 1.9 build cancelled (Causing build to fail because of unresolved "curl -A "$CURL_USER_AGENT" -sSf -L --retry 7 'https://julialang-s3.julialang.org/bin/linux/x64/1.9/julia-1.9-latest-linux-x86_64.tar.gz' | tar -C ~/julia -x -z --strip-components=1 -f -
184curl: (22) The requested URL returned error: 404 Not Found
185
186gzip: stdin: unexpected end of file
187tar: Child returned status 1
188tar: Error is not recoverable: exiting now
189The command "curl -A "$CURL_USER_AGENT" -sSf -L --retry 7 'https://julialang-s3.julialang.org/bin/linux/x64/1.9/julia-1.9-latest-linux-x86_64.tar.gz' | tar -C ~/julia -x -z --strip-components=1 -f -" failed and exited with 2 during ."

Author: sambuddhac

.travis.yml

@@ -3,13 +3,10 @@ language: julia
 notifications:
   email: false
 julia:
-  #- 1.0
-  #- 1.3
-  #- 1.5
   - 1.6
   - 1.7
   - 1.8
-  - 1.9
+  #- 1.9
   - nightly
 coveralls: true
 branches: