Fetch PHP versions from GitHub

Instead of using a hardcoded list of PHP versions, we can fetch them
directly from GitHub and have the list always up to date.

bin/list-all

@@ -1,214 +1,14 @@
 #!/usr/bin/env bash
 
-# Each of these values can be used to build the url to the archive containing
-# the source code for each version
-# (e.g. https://php.net/get/php-<version_name>.tar.gz/from/a/mirror)
+versions=$(curl -s https://api.github.com/repos/php/php-src/git/refs/tags | # Fetch all tags
+          grep '"ref":' | # Filter by refs
+          grep 'php-' | # Filter only those related to php-xxxx
+          grep -Ev "beta|alpha|RC" | # Remove betas, alphas and RCs
+          sed 's/\"ref\"://' | # Remove '"ref":'
+          sed 's/\"refs\/tags\/php-//' | # Remove '"refs/tags/php-"'
+          sed 's/\",//' | # Remove last '",'
+          sort -V) # Sort by version
 
-versions_list=(
-    7.0.2
-    7.0.1
-    7.0.0
-    5.6.17
-    5.5.31
-    5.6.16
-    5.5.30
-    5.6.15
-    5.6.14
-    5.6.13
-    5.5.29
-    5.5.28
-    5.6.12
-    5.6.11
-    5.5.27
-    5.6.10
-    5.5.26
-    5.6.9
-    5.5.25
-    5.6.8
-    5.5.24
-    5.6.7
-    5.5.23
-    5.6.6
-    5.5.22
-    5.6.5
-    5.5.21
-    5.6.4
-    5.5.20
-    5.6.3
-    5.5.19
-    5.6.2
-    5.5.18
-    5.6.1
-    5.5.17
-    5.6.0
-    5.5.16
-    5.5.15
-    5.5.14
-    5.5.13
-    5.5.12
-    5.5.11
-    5.5.10
-    5.5.9
-    5.5.8
-    5.5.7
-    5.5.6
-    5.5.5
-    5.5.4
-    5.5.3
-    5.5.2
-    5.5.1
-    5.5.0
-    5.4.45
-    5.4.44
-    5.4.43
-    5.4.42
-    5.4.41
-    5.4.40
-    5.4.39
-    5.4.38
-    5.4.37
-    5.4.36
-    5.4.35
-    5.4.34
-    5.4.33
-    5.4.32
-    5.4.31
-    5.4.30
-    5.4.29
-    5.4.28
-    5.4.27
-    5.4.26
-    5.4.25
-    5.4.24
-    5.4.23
-    5.4.22
-    5.4.21
-    5.4.20
-    5.4.19
-    5.4.18
-    5.4.17
-    5.4.16
-    5.4.15
-    5.4.14
-    5.4.13
-    5.4.12
-    5.4.11
-    5.4.10
-    5.4.9
-    5.4.8
-    5.4.7
-    5.4.6
-    5.4.5
-    5.4.4
-    5.4.3
-    5.4.2
-    5.4.1
-    5.4.0
-    5.3.29
-    5.3.28
-    5.3.27
-    5.3.26
-    5.3.25
-    5.3.24
-    5.3.23
-    5.3.22
-    5.3.21
-    5.3.20
-    5.3.19
-    5.3.18
-    5.3.17
-    5.3.16
-    5.3.15
-    5.3.14
-    5.3.13
-    5.3.12
-    5.3.11
-    5.3.10
-    5.3.9
-    5.3.8
-    5.3.7
-    5.3.6
-    5.3.5
-    5.3.4
-    5.2.17
-    5.2.16
-    5.2.15
-    5.3.3
-    5.2.14
-    5.3.2
-    5.2.13
-    5.3.1
-    5.2.12
-    5.2.11
-    5.3.0
-    5.2.10
-    5.2.9
-    5.2.8
-    5.2.6
-    5.2.5
-    5.2.4
-    5.2.3
-    5.2.2
-    5.2.1
-    5.2.0
-    5.1.6
-    5.1.5
-    5.1.4
-    5.1.3
-    5.1.2
-    5.1.1
-    5.1.0
-    5.0.5
-    5.0.4
-    5.0.3
-    5.0.2
-    5.0.1
-    5.0.0
-    4.4.9
-    4.4.8
-    4.4.7
-    4.4.6
-    4.4.5
-    4.4.4
-    4.4.3
-    4.4.2
-    4.4.1
-    4.4.0
-    4.3.11
-    4.3.10
-    4.3.9
-    4.3.8
-    4.3.7
-    4.3.6
-    4.3.5
-    4.3.4
-    4.3.3
-    4.3.2
-    4.3.1
-    4.3.0
-    4.2.3
-    4.2.2
-    4.2.1
-    4.2.0
-    4.1.2
-    4.1.1
-    4.1.0
-    4.0.6
-    4.0.5
-    4.0.4
-    4.0.3
-    4.0.2
-    4.0.1
-    4.0.0
-)
-
-versions=""
-sorted_versions=($(printf '%s\n' "${versions_list[@]}"|sort))
-
-# Concatenate all the versions together separated by spaces
-for version in "${sorted_versions[@]}";  do
-      versions="${versions} ${version}"
-done
-
-# Print out the versions
-echo $versions
+# As per the documentation, all versions should be in a single line separated
+# by spaces. We use `xargs` for this.
+echo $versions | xargs