minor #4784 Travis CI - Use multiple keyservers (ktomk)

This PR was squashed before being merged into the 2.15 branch (closes #4784).

Discussion
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Travis CI - Use multiple keyservers

See messages for detailed description.

Adresses failures on running dev-tools install shell script on travis as reported in #4770

Commits
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a68bd01 Travis CI - Use multiple keyservers

Author: keradus

dev-tools/install.sh

@@ -28,12 +28,19 @@ echo λλλ phive
 if [ ! -x bin/phive ]; then
     wget -Obin/phive https://phar.io/releases/phive.phar
     wget -Obin/phive.asc https://phar.io/releases/phive.phar.asc
-    gpg --keyserver pool.sks-keyservers.net --recv-keys 0x9D8A98B29B2D5D79
+    gpg --list-keys 0x9D8A98B29B2D5D79 \
+        || gpg --keyserver ha.pool.sks-keyservers.net --recv-keys 0x9D8A98B29B2D5D79 \
+        || gpg --keyserver keys.fedoraproject.org --recv-keys 0x9D8A98B29B2D5D79 \
+        || gpg --keyserver keyserver.ubuntu.com --recv-keys 0x9D8A98B29B2D5D79 \
+        || gpg --keyserver pgp.mit.edu --recv-keys 0x9D8A98B29B2D5D79
     gpg --verify bin/phive.asc bin/phive
     chmod u+x bin/phive
 fi
 bin/phive --version
 
+echo λλλ phive packages
+./bin/phive install --trust-gpg-keys D2CCAC42F6295E7D,8E730BA25823D8B5,CF1A108D0E7AE720
+
 echo λλλ checkbashisms
 if [ ! -x bin/checkbashisms ]; then
     wget -Obin/checkbashisms https://sourceforge.net/projects/checkbaskisms/files/${VERSION_CB}/checkbashisms/download
@@ -53,7 +60,3 @@ bin/shellcheck --version
 echo λλλ composer packages
 composer update
 composer info -D | sort
-
-echo λλλ phive packages
-
-./bin/phive install --trust-gpg-keys D2CCAC42F6295E7D,8E730BA25823D8B5,CF1A108D0E7AE720