[librsvg] Don't use str.trim_left/right, use trim_start/end, bump Rust to 1.30

[Federico Mena Quintero <federico src gnome org>]

commit 539fdfa4548b136c6a93ee73c600c1cd6606515b
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri Feb 15 19:08:08 2019 -0600

    Don't use str.trim_left/right, use trim_start/end, bump Rust to 1.30

 COMPILING.md                | 2 +-
 configure.ac                | 2 +-
 rsvg_internals/src/space.rs | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/COMPILING.md b/COMPILING.md
index a5132d6c..0cf220db 100644
--- a/COMPILING.md
+++ b/COMPILING.md
@@ -32,7 +32,7 @@ minimum version is listed here; you may use a newer version instead.
 **Compilers:**
 
 * a C compiler and `make` tool; we recommend GNU `make`.
-* rust 1.27 or later
+* rust 1.30 or later
 * cargo
 
 **Mandatory dependencies:**
diff --git a/configure.ac b/configure.ac
index b37d1079..6818ebc9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -113,7 +113,7 @@ AS_IF(test x$RUSTC = xno,
 dnl Minimum version of rustc that we support
 dnl If you change this, please update COMPILING.md
 MINIMUM_RUST_MAJOR=1
-MINIMUM_RUST_MINOR=27
+MINIMUM_RUST_MINOR=30
 
 rust_version=`$RUSTC --version`
 version=`echo "$rust_version" | sed -e 's/^rustc //g'`
diff --git a/rsvg_internals/src/space.rs b/rsvg_internals/src/space.rs
index 4350db28..26276f45 100644
--- a/rsvg_internals/src/space.rs
+++ b/rsvg_internals/src/space.rs
@@ -34,11 +34,11 @@ fn normalize_default(elements: NormalizeDefault, s: &str) -> String {
     let mut s = s;
 
     if !elements.has_element_before {
-        s = s.trim_left();
+        s = s.trim_start();
     }
 
     if !elements.has_element_after {
-        s = s.trim_right();
+        s = s.trim_end();
     }
 
     s.chars()