tests: don't run testinstall in testtravis

... since we already run those in a separate Travis job. This saves us some
time which we can use to run more teststandard tests.

Also, run the 32/64 bit specific tests.

tst/testtravis.g

@@ -5,10 +5,9 @@
 ##
 #Y  Copyright (C) 2015, The GAP Group
 ##
-##  This file runs a selection of tests from 'tst/testinstall' and
-##  'tst/teststandard' directories of the GAP distribution. This
-##  selection omits some longer tests from 'tst/teststandard' to
-##  match Travis CI resource limits. To run it, use this command:
+##  This file is similar to teststandard.g, but skips the 'tst/testinstall'
+##  tests, which are run by a separate Travis job; this help us match Travis
+##  CI resource limits. To run it, use this command:
 ##
 ##  gap> Read( Filename( DirectoriesLibrary( "tst" ), "testtravis.g" ) );
 ##
@@ -17,7 +16,8 @@ Print( "You should start GAP4 using `gap -A -x 80 -r -m 100m -o 1g -K 2g'.\n\n"
 
 TestDirectory( [
   Filename( DirectoriesLibrary( "tst" ), "teststandard" ),
-  Filename( DirectoriesLibrary( "tst" ), "testinstall" )],
+  Filename( DirectoriesLibrary( "tst" ),
+       Concatenation("test", String(8*GAPInfo.BytesPerVariable), "bit"))],
   rec(exitGAP := true) );
 
 # Should never get here